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Introduction to Information Systems
Chapter 1 Introduction to Information Systems
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Information Concepts (1)
Data vs. Information Data Raw facts Distinct pieces of information, usually formatted in a special way Information A collection of facts organized in such a way that they have additional value beyond the value of the facts themselves
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Data ‘Discussion’ (1) (1) Distinct pieces of information, usually formatted in a special way. All software is divided into two general categories: data and programs. Programs are collections of instructions for manipulating data. Data can exist in a variety of forms -- as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind. Strictly speaking, data is the plural of datum, a single piece of
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information. In practice, however, people use data as both the
singular and plural form of the word. (2) The term data is often used to distinguish binary machine-readable information from textual human-readable information. For example, some applications make a distinction between data files (files that contain binary data) and text files (files that contain ASCII data). (3) In database management systems, data files are the files that store the database information, whereas other files, such as index files and data dictionaries, store administrative information, known as metadata.
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Homework Q Is the term “data”generally used in the singular or plural
(a) in the textbook, and (b) in the zdwebopedia web site?
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Terminology Process A set of logically related tasks performed to achieve a defined outcome (n) An executing program. The term is used loosely as a synonym of task. (v) To perform some useful operations on data.
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Terminology Knowledge Knowledge base
An awareness and understanding of a set of information and how that information can be made useful to support a specific task Knowledge base The collection of data, rules, procedures, and relationships that must be followed to achieve value or the proper outcome
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Types of Data Data Represented by Alphanumeric data
Numbers, letters, and other characters Image data Graphic images or pictures Audio data Sound, noise, tones Video data Moving images or pictures
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Data Information Data Transformation Information
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Characteristics of Valuable Information
Accurate, complete, economical, flexible, reliable, relevant, simple, timely, verifiable, accessible, secure
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System System A set of elements or components that interact to accomplish goals A combination of components working together
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System ‘Discussion’ (1) Refers to a combination of components working together. For example, a computer system includes both hardware and software. A Windows system is a personal computer running the Windows operating system. A desktop publishing system is a computer running desktop publishing software. (2) Short for computer system. (3) Short for operating system. (4) An organization or methodology. The binary numbering system, for instance, is a way to count using only two digits.
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System Elements Inputs Processing mechanisms Outputs
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System Example System Elements Goal Inputs Processing elements Outputs
Movie Actors, director, staff, sets, equipment Filming, editing, special effects, distribution Finished film delivered to movie studio Entertaining movie, film awards, profits
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System Components and Concepts
System boundary Defines the system and distinguishes it from everything else System types Simple vs. complex Open vs. closed Stable vs. dynamic Adaptive vs. nonadaptive Permanent vs. temporary
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System Performance and Standards
Efficiency A measure of what is produced divided by what is consumed Effectiveness A measure of the extent to which a system achieves its goals System performance standard A specific objective of the system (next 2 slides)
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Figure 1.5a
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Figure 1.5b
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System Variables and Parameters
A quantity or item that can be controlled by the decision maker E.g. the price a company charges for a product System parameter A value or quantity that cannot be controlled by the decision maker E.g., cost of a raw material
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Modeling a System Model Types of models
An abstraction or an approximation that is used to represent reality Types of models Narrative (aka descriptive) Physical Schematic Mathematical Next slide
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Information System (IS)
Definition A set of interrelated elements or components that collect (input), manipulate (process), and disseminate (output) data and information and provide a feedback mechanism to meet an objective (IS) Pronounced as separate letters, and short for Information Systems or Information Services. For many companies, IS is the name of the department responsible for computers, networking and data management. Other companies refer to the department as IT (Information Technology) and MIS (Management Information Services).
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What is an Information System?
Schematic model of an information system Feedback Input Processing Output
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Input, Processing, Output,
The activity of gathering and capturing data Whatever goes into the computer Processing Converting or transforming data into useful outputs Output Useful information, usually in the form of documents and/or reports Anything that comes out of a computer
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Input ‘Discussion’ (n) Whatever goes into the computer. Input can take a variety of forms, from commands you enter on a keyboard to data from another computer or device. A device that feeds data into a computer, such as a keyboard or mouse, is called an input device. (v) The act of entering data into a computer
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Output ‘Discussion’ (n) Anything that comes out of a computer. Output can be meaningful information or gibberish, and it can appear in a variety of forms -- as binary numbers, as characters, as pictures, and as printed pages. Output devices include display screens, loudspeakers, and printers. (v) To give out. For example, display screens output images, printers output print, and loudspeakers output sounds.
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Feedback Feedback Forecasting
Output that is used to make changes to input or processing activities Forecasting A proactive approach to feedback Use for estimating future sales or inventory needs
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Manual vs. Computerized Systems
Manual systems still widely used E.g., some investment analysts manual draw charts and trend lines to assist them in making investment decisions Computerized systems E.g., the above trends lines can be drawn by computer Evolution Many computerized system began as manual systems E.g., directory assistance (“411”)
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Computer-based Information Systems
A CBIS is composed of… Hardware Software Databases Telecommunications People Procedures Together they are… Configured to collect, manipulate, store, and process data into information
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Technology Infrastructure
Another term for CBIS Consists of the shared information system (IS) resources that form the foundation of the information system
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Hardware Hardware Computer equipment used to perform input, processing, and output activities The objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips.
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Hardware ‘Discussion’
Hardware refers to objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips. In contrast, software is untouchable. Software exists as ideas, concepts, and symbols, but it has no substance. Books provide a useful analogy. The pages and the ink are the hardware, while the words, sentences, paragraphs, and the overall meaning are the software. A computer without software is like a book full of blank pages -- you need software to make the computer useful just as you need words to make a book meaningful.
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Software Software Computer programs that govern/determine/control the operation of the computer Computer instructions or data
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Software ‘Discussion’ (1)
Software is computer instructions or data. Anything that can be stored electronically is software. The storage devices and display devices are hardware. The terms software and hardware are used as both nouns and adjectives. For example, you can say: "The problem lies in the software," meaning that there is a problem with the program or data, not with the computer itself. You can also say: "It's a software problem.“
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Software ‘Discussion’ (2)
The distinction between software and hardware is sometimes confusing because they are so integrally linked. Clearly, when you purchase a program, you are buying software. But to buy the software, you need to buy the disk (hardware) on which the software is recorded. Software is often divided into two categories. Systems software includes the operating system and all the utilities that enable the computer to function. Applications software includes programs that do real work for users. For example, word processors, spreadsheets, and database management systems fall under the category of applications software.
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Database Database An organized collection of facts and information
A collection of information organized in such a way that a computer program can quickly select desired pieces of data
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Database ‘Discussion’ (1)
A database is a collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system. Traditional databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. For example, a telephone book is analogous to a file. It contains a list of records, each of which consists of three fields: name, address, and telephone number.
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Database ‘Discussion’ (2)
An alternative concept in database design is known as Hypertext. In a Hypertext database, any object, whether it be a piece of text, a picture, or a film, can be linked to any other object. Hypertext databases are particularly useful for organizing large amounts of disparate information, but they are not designed for numerical analysis. To access information from a database, you need a database management system (DBMS). This is a collection of programs that enables you to enter, organize, and select data in a database.
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Database ‘Discussion’ (3)
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Telecommunications Telecommunications
The electronic transmission of signals for communications; enables organizations to link computer systems into effective networks Refers to all types of data transmission, from voice to video
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Parts of a CBIS Five parts Hardware Software Database
Telecommunications Networks
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Networks Network Used to connect computers and computer equipment in a building, around the country, across the world, to enable electronic communications A group of two or more computer systems linked together
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Network ‘Discussion’ (1)
There are many types of computer networks, including: local-area networks (LANs) : The computers are geographically close together (that is, in the same building). wide-area networks (WANs) : The computers are farther apart and are connected by telephone lines or radio waves.
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Network ‘Discussion’ (2)
In addition to these types, the following characteristics are also used to categorize different types of networks: topology : The geometric arrangement of a computer system. Common topologies include a bus, star, and ring. protocol : The protocol defines a common set of rules and signals that computers on the network use to communicate. One of the most popular protocols for LANs is called Ethernet. Another popular LAN protocol for PCs is the IBM token-ring network . architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture.
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Network ‘Discussion’ (3)
Computers on a network are sometimes called nodes. Computers and devices that allocate resources for a network are called servers.
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Network ‘Discussion’ (4)
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Internet and Intranet Internet Intranet
The world’s largest telecommunications network A network of networks Free exchange of information A global network connecting millions of computers Intranet A network that uses Internet technology within an organization A network belonging to an organization
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People and Procedures People Procedures
The most important element in most computer- based information systems Includes people who manage, run, program, and maintain the system E.g., IT professionals (you!) Procedures Includes the strategies, policies, methods, and rules for using the CBIS
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Business Information Systems
Types Transaction processing systems E-commerce systems Management information systems Decision support systems Expert systems
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Transactions Processing Systems
Any business-related exchange E.g., generating a weekly payroll Transaction processing system (TPS) An organized collection of people, procedures, software, databases, and devices used to record completed for for business related exchanges
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Payroll transaction processing
Payroll Example Hours worked Payroll transaction processing Payroll checks Pay rate
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Business Information Systems
Types Transaction processing systems E-commerce systems Management information systems Decision support systems Expert systems
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E-Commerce System E-commerce
Involves any business transaction executed electronically Conducting business on-line For example, between… Companies Companies and consumers Business and the public sector Consumers and the public sector Example for placing a purchase order
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Purchase Order - Traditional
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Purchase Order – E-commerce
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Business Information Systems
Types Transaction processing systems E-commerce systems Management information systems Decision support systems Expert systems
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Management Information Systems
An MIS is… An organized collection of people, procedures, software, databases, and devices used to provide routine information to managers and decision makers
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Schematic of MIS Marketing management Manufacturing management
information system Manufacturing management Information system Common databases Financial management Information system Order management information system TPS
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MIS ‘Discussion’ Short for management information system or management
information services, and pronounced as separate letters, MIS refers to a class of software that provides managers with tools for organizing and evaluating their department. Typically, MIS systems are written in COBOL and run on mainframes or minicomputers. Within companies and large organizations, the department responsible for computer systems is sometimes called the MIS department. Other names for MIS include IS (Information Services) and IT (Information Technology).
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Business Information Systems
Types Transaction processing systems E-commerce systems Management information systems Decision support systems Expert systems
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Decision Support Systems
A DSS is… An organized collection of people, procedures, software, databases, and devices used to support problem-specific decision making A DSS helps a manger “do the right thing”
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Business Information Systems
Types Transaction processing systems E-commerce systems Management information systems Decision support systems Expert systems
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Expert Systems An expert system is…
A computer application that performs a task that would otherwise be performed by a human expert gives the computer the ability to make suggestions and to act like an expert in a particular field Examples: diagnose human illnesses, make financial forecasts, schedule routes for delivery vehicles Expert systems typically include “artificial intelligence” (next slide)
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Artificial Intelligence (1)
The branch of computer science concerned with making computers behave like humans. The term was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology. Artificial intelligence includes games playing: programming computers to play games such as chess and checkers expert systems : programming computers to make decisions in real-life situations (for example, some expert systems help doctors diagnose diseases based on symptoms) natural language : programming computers to understand natural human languages
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Artificial Intelligence (2)
neural networks : Systems that simulate intelligence by attempting to reproduce the types of physical connections that occur in animal brains robotics : programming computers to see and hear and react to other sensory stimuli Currently, no computers exhibit full artificial intelligence (that is, are able to simulate human behavior). The greatest advances have occurred in the field of games playing. The best computer chess programs are now capable of beating humans. In May, 1997, an IBM super-computer called Deep Blue defeated world chess champion
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Artificial Intelligence (3)
Gary Kasparov in a chess match. In the area of robotics, computers are now widely used in assembly plants, but they are capable only of very limited tasks. Robots have great difficulty identifying objects based on appearance or feel, and they still move and handle objects clumsily. Natural-language processing offers the greatest potential rewards because it would allow people to interact with computers without needing any specialized knowledge. You could simply walk up to a
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Artificial Intelligence (4)
computer and talk to it. Unfortunately, programming computers to understand natural languages has proved to be more difficult than originally thought. Some rudimentary translation systems that translate from one human language to another are in existence, but they are not nearly as good as human translators. There are also voice recognition systems that can convert spoken sounds into written words, but they do not understand what they are writing; they simply take dictation. Even these systems are quite limited -- you must speak slowly and distinctly.
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Artificial Intelligence (5)
In the early 1980s, expert systems were believed to represent the future of artificial intelligence and of computers in general. To date, however, they have not lived up to expectations. Many expert systems help human experts in such fields as medicine and engineering, but they are very expensive to produce and are helpful only in special situations. Today, the hottest area of artificial intelligence is neural networks, which are proving successful in a number of disciplines such as voice recognition and natural-language processing.
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Artificial Intelligence (6)
There are several programming languages that are known as AI languages because they are used almost exclusively for AI applications. The two most common are LISP and Prolog.
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Working with Systems (1)
Systems development The activity of creating or modifying an existing business system Systems investigation and analysis Defines the problems and opportunities of an existing system Systems design Determine how a new system will work to meet business needs
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Working with Systems (2)
Systems implementation Creating and acquiring system components defined in the design Systems maintenance and review Checks and modifies the system so that it continues to meet changing business needs
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End of Chapter 1 Chapter 2
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Information Systems in Organizations
Chapter 2 Information Systems in Organizations
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Organizations and Information Systems
A formal collection of people and other resources established to accomplish a set of goals
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General Model of an Organization
(next slide)
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Value Chain Term coined by Michael Porter in a article in the Harvard Business Review Def: a series of activities that includes inbound logistics, warehouse and storage, production, finished product storage, outbound logistics, marketing and sales, and customer service Schematic
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Organizations Organizational structure
Organizational subunits and the way they are related to the overall organization Traditional organizational structure Major department heads report to a president or top-level manager Schematic
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Traditional Organizational Structure
S. Burry, President Bailey, Legal counsel B. Wong, VP Accounting C.Rodrig, VP Information Systems R. Henderson, VP Marketing K. Kelly, VP Production V. Cisborn, VP Human Resources S. Samuel Supervisor L. Bashran, Supervisor Traditional Organizational Structure
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Terminology (1) Hierarchical organizational structure
See previous slide Series of levels Those at high levels have more power and authority within an organization Flat organizational structure An organizational structure with a reduced number of layers of management
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Terminology (2) Empowerment
Giving employees and their managers more power, responsibility, and authority to make decisions, take certain actions, and have more control over their jobs
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Other Organizational Structures (1)
Schematic Project organizational structure An organization structure centred on major products or services Contrast with traditional structure Team organizational structure An organizational structure centred on work teams or groups
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Project Organizational Structure
B. Woods, President Air & Aerospace Co. T. Walker, Senior VP, Aircraft Division W. Butler, Senior VP, Aerospace Division O. Teco, Senior VP, Communications & Satellite Division VP, Finance VP, Marketing VP, Production VP, Sales VP, Finance VP, Marketing VP, Production VP, Sales VP, Finance VP, Marketing VP, Production Project Organizational Structure
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Other Organizational Structures (2)
Multidimensional organizational structure A structure that may incorporate several structures at the same time Schematic
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Vice President, Marketing Vice President, Production
Vice President, Finance Publisher, College Division Marketing Group Production Group Finance Group Publisher, Trade Division Publisher, High School Division Multidimensional Organizational Structure
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Other Organizational Structures (3)
Advantages and disadvantages of different organizational structures Read the book!
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Organizational Culture and Change (1)
A set of major understandings and assumptions shared by a group Organizational culture The major understandings and assumptions for a business, a corporation, or an organization
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Organizational Culture and Change (1)
Organizational change Deals with how for-profit and non-profit organizations plan for, implement, and handle change Organizational learning The way organizations adapt to new conditions or alter their practices over time
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Models of Change ‘Change model’
A representation of change theories developed by Kurt Lewin and Edgar Schein in 1969 Three-stage approach Unfreezing Moving Refreezing Schematic
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Change Model
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Reengineering Also called ‘Process redesign’
The radical redesign of business processes, organizational structures, information systems, and values of the organization to achieve a breakthrough in business results For example, to… Reduce delivery time Increase product and service quality Improve customer satisfaction Increase revenues and profitability
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Rules, Rules, Rules Reengineering requires finding and vigorously challenging old rules Rule Original rationale Potential problem Small orders held until full truckload Reduce delivery costs Customer deliver is delayed No order accepted until credit approved Reduce potential for bad debt Customer service is poor All product decisions made at headquarters Reduce number of items in inventory Perception of limited product selection
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Other Models Continuous improvement
Constantly seeking ways to improve the business processes to add value to products and services
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Continuous Improvement vs. Reengineering
Strong action to solve serious problem Routine action Driven by senior executives Worker-driven Broad in scope; cuts across organizations Narrow in scope Goal to achieve a major breakthrough Continuous, gradual Often led by outsiders Led by workers IS integral to the solution IS provides data to guide
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Total Quality Management
The ability of a product (including service) to meet or exceed customer expectations TQM A collection of approaches, tools, and techniques, that offers a commitment to quality throughout the organization
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Outsourcing and Downsizing
Contracting with outside professional services to meet specific business needs E.g., advertising, hiring Downsizing Reducing the number of employees to cut costs Also called ‘rightsizing’ May have serious side effects E.g., low employee morale, a need for expensive consultants, lost time, waning productivity
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Competitive Advantage
A position, product, service, etc., within a business that improves a position within a market with respect to competitors Porter’s ‘Five force’ model of competitive advantage Identifies factors that lead to competitiveness Schematic
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Substitute Products Buyer Power Supplier Power Rivalry New Entrants
Porter’s Five-force Model
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Strategic Planning for Competitive Advantage
Four techniques: Strategic alliances (aka strategic partnerships) Creating new goods or services Improving existing goods or services Using information systems for strategic purposes Next slide
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Strategic alliance An agreement between two or more companies that involves the joint production and distribution of goods and services E.g., Chrysler + Daimler Benz Creating new goods or services A company may become stagnant without the introduction of new goods and/or services E.g., Compaq, Dell Improving existing goods or services Small variations to existing goods or services, and/or complete modifications E.g., “light” foods Using information systems for strategic purposes IS for improving organizational effectiveness E.g., SABRE (airline reservation system)
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Performance-based Information Systems
Productivity A measure of the output achieved divided by the input required Productivity = Output achieved Input required
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Productivity An example is given in the top paragraph on p. 65
This is a bad example! Why?
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Return on Investments (ROI) and the Value of IS
Return on investment (ROI) A measure of IS value that investigates the additional profits or benefits that are generated as a percentage of the investment in information systems technology represents
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Measures of IS Value Earnings growth Market share
Customer awareness and satisfaction One of my favourite quotes: When you cannot measure, your knowledge is of a meager and unsatisfactory kind. Kelvin
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Justifying IS Categories: Tangible savings Intangible savings
Legal requirements Modernization Pilot project
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Roles, Functions, and Careers in the IS Department
Categories: Operations Systems development Support Liaisons (information service units) Schematic
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IS Department CEO CIO Other functional areas Operations
Information Resource Management Functions Operations Systems development Support Information service unit Computer facility operations Systems analysis & design Data administration Data entry Information centre Programming Information technololgy Local Area network operations IS Department
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Information Centre Information centre
Provides users with assistance, training, application development, documentation, equipment selection and setup, standards, technical assistance, and troubleshooting
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Information Service Unit
Attached to a functional area of the business. Acts as a local information support organization within a functional area. Performs the critical role of liaison between the functional area and IS
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Chief Information Officer (CIO)
A manager at the vice-president level responsible for IS planning, policy, and standards Focused on supporting corporate goals
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Other IS Roles Database Administrator Systems Programmer
Network Specialist LAN Administrator Webmaster Trainer
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IS Principles Use of IS strongly influenced by organizational structure and problem orientations IS are often intertwined within the value-added processes IS usage may require change that could meet with resistance Value-added IS needs to be continually sought
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End of Chapter 2 Chapter 3
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Hardware, Input, Processing, and Output Devices
Chapter 3 Hardware, Input, Processing, and Output Devices
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Hardware Hardware Any machinery (most of which uses digital circuits) that assists in the input, processing, storage, and output activities of an information system
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Hardware Components Central processing unit (CPU)
A hardware component that performs computing functions utilizing the ALU, control unit, and registers. Arithmetic/logic unit (ALU) Performs mathematical calculations and makes logical comparisons Control unit Sequentially accesses program instructions, decodes them, coordinates flow of data in/out of ALU, registers, primary and secondary storage, and various output devices
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Hardware Components Registers
High-speed storage areas used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU Primary storage Holds program instructions and data (a.k.a. main memory) Schematic
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Communications devices
Processing device Control unit Arithmetic/ logic unit Input devices Output devices Register storage area Memory Secondary storage
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Execution of an Instruction
Machine cycle Instruction phase Execution phase Step 1: Fetch instruction Step 2: Decode instruction Execute phase Step 3: Execute instruction Step 4: Store results Schematic
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Processing device (2) Decode (3) Execute I-time E-time (1) Fetch
Control unit ALU (2) Decode (3) Execute I-time E-time Registers (1) Fetch (4) Store Memory
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Pipelining Pipelining
A CPU operation in which multiple execution phases are performed in a single machine cycle
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Machine Cycle Time Machine cycle time
Time it takes to execute an instruction Slow machines Measured in microseconds (one-millionth of a second) Fast machines Measured in nanoseconds (one-billionth of a second) to picoseconds (one-trillionth of a second) MIPS Millions of instructions per second
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MIPS ‘Discussion’ (1) Acronym for million instructions per second. An old measure of a computer's speed and power, MIPS measures roughly the number of machine instructions that a computer can execute in one second. However, different instructions require more or less time than others, and there is no standard method for measuring MIPS. In addition, MIPS refers only to the CPU speed, whereas real applications are generally limited by other factors, such as I/O speed. A machine with a high MIPS rating, therefore, might not run a particular application any faster than a machine with a low MIPS rating. For all these reasons, MIPS ratings are not used often anymore. In fact, some people jokingly claim that MIPS really stands for Meaningless Indicator of Performance.
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MIPS ‘Discussion’ (2) Despite these problems, a MIPS rating can give you a general idea of a computer's speed. The IBM PC/XT computer, for example, is rated at ¼ MIPS, while Pentium- based PCs run at over 100 MIPS.
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Cycle Time
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Clock Speed Clock speed Hertz (Hz) Megahertz (MHz)
Predetermined rate a CPU produces a series of electronic pulses. Hertz (Hz) One cycle or pulse per second Megahertz (MHz) Millions of cycles per second
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Wordlength Wordlength
Number of bits the CPU can process at any one time BIT ‘Binary digit’ - 0 or 1 that combine to form a “word” Computer word What the computer processes Microcode Predefined, elementary circuits and logical operations that the processor performs when it executes an instruction
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Bit ‘Discussion’ (1) Short for binary digit, the smallest unit of information on a machine. The term was first used in 1946 by John Tukey, a leading statistician and adviser to five presidents. A single bit can hold only one of two values: 0 or 1. More meaningful information is obtained by combining consecutive bits into larger units. For example, a byte is composed of 8 consecutive bits.
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Bit ‘Discussion’ (2) Computers are sometimes classified by the number of bits they can process at one time or by the number of bits they use to represent addresses. These two values are not always the same, which leads to confusion. For example, classifying a computer as a 32-bit machine might mean that its data registers are 32 bits wide or that it uses 32 bits to identify each address in memory. Whereas larger registers make a computer faster, using more bits for addresses enables a machine to support larger programs.
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Bit ‘Discussion’ (3) Graphics are also often described by the number of bits used to represent each dot. A 1-bit image is monochrome; an 8-bit image supports 256 colors or grayscales; and a 24- or 32-bit graphic supports true color.
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Bus Bus Bus width Physical wiring connecting computer components
Number of bits a bus can transfer at one time
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Bus ‘Discussion’ (1) (1) A collection of wires through which data is transmitted from one part of a computer to another. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory. There's also an expansion bus that enables expansion boards to access the CPU and memory. All buses consist of two parts -- an address bus and a data bus. The data bus transfers actual data whereas the address bus transfers information about where the data should go.
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Bus ‘Discussion’ (2) The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time. For example, a 16-bit bus can transmit 16 bits of data, whereas a 32-bit bus can transmit 32 bits of data. Every bus has a clock speed measured in MHz. A fast bus allows data to be transferred faster, which makes applications run faster. On PCs, the old ISA bus is being replaced by faster buses such as PCI.
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Bus ‘Discussion’ (3) Nearly all PCs made today include a local bus for data that requires especially fast transfer speeds, such as video data. The local bus is a high-speed pathway that connects directly to the processor. Several different types of buses are used on Apple Macintosh computers. Older Macs use a bus called NuBus, but newer ones use PCI. (2) In networking, a bus is a central cable that connects all devices on a local-area network (LAN). It is also called the backbone.
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Moore’s Law Moore’s Law
A hypothesis that states transistor densities in a single chip will double every 18 months Schematic
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Moore’s Law ‘Discussion’
The observation made in 1965 by Gordon Moore, co- founder of Intel, that the number of transistors per square inch on integrated circuits had doubled every year since the integrated circuit was invented. Moore predicted that this trend would continue for the foreseeable future. In subsequent years, the pace slowed down a bit, but data density has doubled approximately every 18 months, and this is the current definition of Moore's Law, which Moore himself has blessed. Most experts, including Moore himself, expect Moore's Law to hold for at least another two decades.
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Instruction Sets Complex instruction set computing (CISC)
A computer chip design that places as many microcode instructions into the central processor as possible. Reduced instruction set computing (RISC) A computer chip design based on reducing the number of microcode instructions built into a chip to an essential set of common microcode instructions
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RISC ‘Discussion’ (1) Pronounced “risk”, acronym for reduced instruction set computer, a type of microprocessor that recognizes a relatively limited number of instructions. Until the mid- 1980s, the tendency among computer manufacturers was to build increasingly complex CPUs that had ever-larger sets of instructions. At that time, however, a number of computer manufacturers decided to reverse this trend by building CPUs capable of executing only a very limited set of instructions. One advantage of reduced instruction set computers is that they can execute their instructions very fast because the instructions are so simple.
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RISC ‘Discussion’ (2) Another, perhaps more important advantage, is that RISC chips require fewer transistors, which makes them cheaper to design and produce. Since the emergence of RISC computers, conventional computers have been referred to as CISCs (complex instruction set computers). There is controversy among experts about the ultimate value of RISC architectures. Its proponents argue that RISC machines are both cheaper and faster, and are therefore the machines of the future. Skeptics note that by making the hardware simpler, RISC architectures put a greater burden on the software. They argue that this is not worth the trouble because conventional microprocessors are increasingly fast and cheap anyway.
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RISC ‘Discussion’ (3) To some extent, the argument is becoming moot because CISC and RISC implementations are becoming more and more alike. Many of today's RISC chips support as many instructions as yesterday's CISC chips. And today's CISC chips use many techniques formerly associated with RISC chips.
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Byte Byte Eight bits together that represent a single character of data
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Byte ‘Discussion’ A byte is a unit of storage capable of holding a single character. On almost all modern computers, a byte is equal to 8 bits. Large amounts of memory are indicated in terms of kilobytes (1,024 bytes), megabytes (1,048,576 bytes), and gigabytes (1,073,741,824 bytes). A disk that can hold megabytes, for example, is capable of storing approximately 1.4 million characters, or about 3,000 pages of information.
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Memory Characteristics and Functions
Random Access Memory - RAM Temporary and volatile Can be read or written Read Only Memory - ROM Permanent and non-volatile Can only be read Schematic
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Semiconductor Memory types Volatile Non-volatile RAM ROM SRAM DRAM PROM EPROM
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RAM ‘Discussion’ (1) Pronounced “ramm”, acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers. There are two basic types of RAM: dynamic RAM (DRAM) static RAM (SRAM)
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RAM ‘Discussion’ (2) Two types: dynamic RAM and static RAM. The two types differ in the technology they use to hold data, dynamic RAM being the more common type. Dynamic RAM needs to be refreshed thousands of times per second. Static RAM does not need to be refreshed, which makes it faster; but it is also more expensive than dynamic RAM. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.
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RAM ‘Discussion’ (3) In common usage, the term RAM is synonymous with main memory, the memory available to programs. For example, a computer with 8M RAM has approximately 8 million bytes of memory that programs can use. In contrast, ROM (read-only memory) refers to special memory used to store programs that boot the computer and perform diagnostics. Most personal computers have a small amount of ROM (a few thousand bytes). In fact, both types of memory (ROM and RAM) allow random access. To be precise, therefore, RAM should be referred to as read/write RAM and ROM as read-only RAM.
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ROM ‘Discussion’ (1) Pronounced “rahm”, acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
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ROM ‘Discussion’ (2) Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. In addition, ROMs are used extensively in calculators and peripheral devices such as laser printers, whose fonts are often stored in ROMs. A variation of a ROM is a PROM (programmable read- only memory). PROMs are manufactured as blank chips on which data can be written with a special device called a PROM programmer .
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Cache Memory Cache memory
High speed memory that a processor can access more rapidly than main memory Schematic
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CPU Memory (main store) Typically 4MB Cache controller Cache memory Typically 64 KB Miss Hit
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Cache ‘Discussion’ (1) Pronounced “cash”, a special high-speed storage mechanism. It can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching. A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.
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Cache ‘Discussion’ (2) Some memory caches are built into the architecture of microprocessors. The Intel microprocessor, for example, contains an 8K memory cache, and the Pentium has a 16K cache. Such internal caches are often called Level 1 (L1) caches. Most modern PCs also come with external cache memory, called Level 2 (L2) caches. These caches sit between the CPU and the DRAM. Like L1 caches, L2 caches are composed of SRAM but they are much larger.
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Cache ‘Discussion’ (3) Disk caching works under the same principle as memory caching, but instead of using high-speed SRAM, a disk cache uses conventional main memory. The most recently accessed data from the disk (as well as adjacent sectors) is stored in a memory buffer. When a program needs to access data from the disk, it first checks the disk cache to see if the data is there. Disk caching can dramatically improve the performance of applications, because accessing a byte of data in RAM can be thousands of times faster than accessing a byte on a hard disk.
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Cache ‘Discussion’ (4) When data are found in the cache, it is called a cache hit, and the effectiveness of a cache is judged by its hit rate. Many cache systems use a technique known as smart caching, in which the system can recognize certain types of frequently used data. The strategies for determining which information should be kept in the cache constitute some of the more interesting problems in computer science.
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Multiprocessing Multiprocessing Coprocessor
The simultaneous execution of two or more instructions at the same time. Coprocessor Speeds processing by executing specific types of instructions (typically floating-point instructions) while the CPU works on another processing activity
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Multiprocessing ‘Discussion’
(1) Refers to a computer system's ability to support more than one process (program) at the same time. Multiprocessing operating systems enable several programs to run concurrently. UNIX is one of the most widely used multiprocessing systems, but there are many others, including OS/2 for high-end PCs. Multiprocessing systems are much more complicated than single-process systems because the operating system must allocate resources to competing processes in a reasonable manner. (2) Refers to the utilization of multiple CPUs in a single computer system. This is also called parallel processing.
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Coprocessor ‘Discussion’
A special-purpose processing unit that assists the CPU in performing certain types of operations. For example, a math coprocessor performs mathematical computations, particularly floating-point operations. Math coprocessors are also called numeric and floating-point coprocessors. Most computers come with a floating-point coprocessors built in. Note, however, that the program itself must be written to take advantage of the coprocessor. If the program contains no coprocessor instructions, the coprocessor will never be utilized. In addition to math coprocessors, there are also graphics coprocessors for manipulating graphic images. These are often called accelerator boards.
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Parallel Processing Parallel processing
A form of multiprocessing that speeds the processing by linking several processors to operate at the same time or in parallel Schematic
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Processing job Part A Part B Part C Part D Part E Processor A Processor B Processor C Processor D Processor E Solution A Solution B Solution C Solution D Solution E Final results
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Parallel Processing ‘Discussion’ (1)
The simultaneous use of more than one CPU to execute a program. Ideally, parallel processing makes a program run faster because there are more engines (CPUs) running it. In practice, it is often difficult to divide a program in such a way that separate CPUs can execute different portions without interferring with each other.
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Parallel Processing ‘Discussion’ (2)
Most computers have just one CPU, but some models have several. There are even computers with thousands of CPUs. With single-CPU computers, it is possible to perform parallel processing by connecting the computers in a network. However, this type of parallel processing requires very sophisticated software called distributed processing software. Note that parallel processing differs from multitasking, in which a single CPU executes several programs at once. Parallel processing is also called parallel computing.
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Secondary Storage Secondary Storage
Stores large amounts of data, instructions, and information more permanently than main memory
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Devices for Secondary Storage
Magnetic tape and disks Compact Disk Read-Only Memory (CD-ROM) Write Once Read Many - (WORM) Magneto-optical disks Redundant Array of Inexpensive Disks (RAID) Optical disks Digital Video Disks Memory cards Flash memory Removable storage
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Access Methods and Storage Devices
Sequential Data retrieved in the order stored. Direct Data retrieved without the need to read or pass other data in sequence Storage Devices Sequential Access Storage Devices (SASDs) Direct Access Storage Devices (DASDs)
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Comparison of Secondary Storage Devices
Storage Device Year Introduced Maximum Capacity 3.5 inch diskette MB CD-ROM MB Zip MB DVD GB
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External SCCI Jazz drive
Cost Comparisons Device DAT tape Hard drive External SCCI Jazz drive 3.5” diskette ZIP Plus drive RAM Cost $49.95 $349.95 $599.95 $0.50 $199.95 $269.95 Storage 10,000MB 6,400MB 2,000MB 1.4MB 100MB 64MB Cost per MB $0.005 $0.05 $0.30 $0.35 $2.00 $4.21
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Input and Output Devices
Data entry The process by which human-readable data is converted into a machine-readable form. Data input The process of transferring machine-readable data into the computer system. Source data automation Capturing and editing data where the data is originally created and in a form that can be directly input to a computer
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Input Devices PC input devices Voice recognition devices
Digital computer cameras Terminals Scanning devices Optical data readers Magnetic Ink Character Recognition (MICR) Point Of Sale (POS) devices Automatic Teller Machine (ATM) Pen input devices Light pens Touch sensitive screens Bar code scanners
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A PC Equipped with a Computer Camera
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MICR Device
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Output Devices Display monitors Liquid Crystal Displays (LCDs)
Printers and plotters Computer Output Microfilm (COM)
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Types of Computer Systems (1)
Personal computers (PCs) Small, inexpensive, often called microcomputers Network computers Used for accessing networks, especially the Internet Workstations Fit between high-end microcomputers and low-end midrange
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Types of Computer Systems (2)
Midrange (or ‘mini’) computers Size of a three drawer file cabinet and accommodates several users at one time Mainframe computers Large and powerful, shared by hundreds concurrently Supercomputers Most powerful with fastest processing speeds
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PC ‘Discussion’ (1) A small, relatively inexpensive computer designed for an individual user. In price, personal computers range anywhere from a few hundred dollars to over five thousand dollars. All are based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. At home, the most popular use for personal computers is for playing games.
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PC ‘Discussion’ (2) Personal computers first appeared in the late 1970s. One of the first and most popular personal computers was the Apple II, introduced in 1977 by Apple Computer. During the late 1970s and early 1980s, new models and competing operating systems seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal computer, known as the IBM PC. The IBM PC quickly became the personal computer of choice, and most other personal computer manufacturers fell by the wayside. One of the few companies to survive IBM's onslaught was Apple Computer, which remains a major player in the personal computer marketplace.
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PC ‘Discussion’ (3) Other companies adjusted to IBM's dominance by building IBM clones, computers that were internally almost the same as the IBM PC, but that cost less. Because IBM clones used the same microprocessors as IBM PCs, they were capable of running the same software. Over the years, IBM has lost much of its influence in directing the evolution of PCs. Many of its innovations, such as the MCA expansion bus and the OS/2 operating system, have not been accepted by the industry or the marketplace.
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PC ‘Discussion’ (4) Today, the world of personal computers is basically divided between Apple Macintoshes and PCs. The principal characteristics of personal computers are that they are single- user systems and are based on microprocessors. However, although personal computers are designed as single-user systems, it is common to link them together to form a network. In terms of power, there is great variety. At the high end, the distinction between personal computers and workstations has faded. High-end models of the Macintosh and PC offer the same computing power and graphics capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and DEC.
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NC ‘Discussion’ (1) An Network Computer (NC) is a computer with minimal memory, disk storage and processor power designed to connect to a network, especially the Internet. The idea behind network computers is that many users who are connected to a network don't need all the computer power they get from a typical personal computer. Instead, they can rely on the power of the network servers.
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NC ‘Discussion’ (2) This is really a variation on an old idea -- diskless workstations -- which are computers that contain memory and a processor but no disk storage. Instead, they rely on a server to store data. Network computers take this idea one step further by also minimizing the amount of memory and processor power required by the workstation. Network computers designed to connect to the Internet are sometimes called Internet boxes, Net PCs, and Internet appliances.
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NC ‘Discussion’ (3) One of the strongest arguments behind network computers is that they reduce the total cost of ownership (TCO) -- not only because the machines themselves are less expensive than PCs, but also because network computers can be administered and updated from a central network server.
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Workstation ‘Discussion’ (1)
(1) A type of computer used for engineering applications (CAD/CAM), desktop publishing, software development, and other types of applications that require a moderate amount of computing power and relatively high quality graphics capabilities. Workstations generally come with a large, high-resolution graphics screen, at least 64 MB (megabytes) of RAM, built-in network support, and a graphical user interface. Most workstations also have a mass storage device such as a disk drive, but a special type of workstation, called a diskless workstation, comes without a disk
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Workstation ‘Discussion’ (2)
drive. The most common operating systems for workstations are UNIX and Windows NT. In terms of computing power, workstations lie between personal computers and minicomputers, although the line is fuzzy on both ends. High-end personal computers are equivalent to low-end workstations. And high-end workstations are equivalent to minicomputers. Like personal computers, most workstations are single-user
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Workstation ‘Discussion’ (3)
computers. However, workstations are typically linked together to form a local-area network, although they can also be used as stand-alone systems. The leading manufacturers of workstations are Sun Microsystems, Hewlett-Packard Company, Silicon Graphics Incorporated, and Compaq. (2) In networking, workstation refers to any computer connected to a local-area network. It could be a workstation or a personal computer.
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Minicomputer ‘Discussion’ (1)
A mid-sized computer. In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously.
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Mainframe Computer ‘Discussion’ (1)
A very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe. The distinction between small mainframes and minicomputers is vague, depending really on how the manufacturer wants to market its machines.
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Supercomputer ‘Discussion’
The fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration. The chief difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently.
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So… Increasing size and power Personal computer Network computer
Workstation Minicomputer Mainframe computer Supercomputer Increasing size and power
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Annual Cost of PC Ownership
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TCO ‘Discussion’ (1) ‘TCO’ is an abbreviation for Total Cost of Ownership. TCO is a very popular buzzword representing how much it actually costs to own a PC. The TCO includes: Original cost of the computer and software Hardware and software upgrades Maintenance Technical support Training
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TCO ‘Discussion’ (2) Most estimates place the TCO at about 3 to 4 times the actual purchase cost of the PC. The TCO has become a rallying cry for companies supporting network computers. They claim that not only are network computers less expensive to purchase, but the TCO is also much less because network computers can be centrally administered and upgraded. Backers of conventional PCs, especially Microsoft and Intel, have countered with Zero Administration for Windows (ZAW), which they claim will also significantly reduce TCO.
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End of Chapter 3 Chapter 4
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Software: Systems and Applications Software
Chapter 4 Software: Systems and Applications Software
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The Importance of Software in Business
High Software $ Hardware Low 1950 today time
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An Overview of Software
What is ‘Software’? See Chapter 1!
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Classes of Software Systems software Application software
Set of programs that coordinates activities and functions of the hardware and various other programs Application software Programs that help users solve particular computing problems
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Spheres of Influence Personal Workgroup Enterprise
Information systems that serve the needs of an individual user Workgroup Two or more people who work together to achieve a common goal Enterprise Information systems that support the firm in its interaction with its environment.
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Issues and Trends Software licensing
Protection by software vendors to prevent unauthorized use Software upgrades A revised version of software that usually includes fixes of known problems, plus enhancements to existing capabilities Global software support Software that is distributed around the globe may require unique support mechanisms due to local political and economic conditions
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Ownership Freeware Shareware Public-domain software
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Freeware Copyrighted software given away for free by the author. Although it is available for free, the author retains the copyright, which means that you cannot do anything with it that is not expressly allowed by the author. Usually, the author allows people to use the software, but not sell it.
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Ownership Freeware Shareware Public-domain software
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Shareware (1) Software distributed on the basis of an honor system. Most shareware is delivered free of charge, but the author usually requests that you pay a small fee if you like the program and use it regularly. By sending the small fee, you become registered with the producer so that you can receive service assistance and updates. You can copy shareware and pass it along to friends and colleagues, but they too are expected to pay a fee if they use the product. Shareware is inexpensive because it is usually produced by a single programmer and is offered directly to customers. Thus, there are
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Shareware (2) practically no packaging or advertising expenses.
Note that shareware differs from public-domain software in that shareware is copyrighted. This means that you cannot sell a shareware product as your own.
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Ownership Freeware Shareware Public-domain software
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Public-domain Software
Refers to any program that is not copyrighted. Public-domain software is free and can be used without restrictions. The term public-domain software is often used incorrectly to include freeware, free software that is nevertheless copyrighted.
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Role of Systems Software
System software… Is an interface or buffer between application software and hardware Controls the computer hardware and acts as an interface with applications programs Schematic
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Operating and systems software
Application software Operating and systems software Users Hardware
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Operating System Functions
Perform common computer hardware functions Provide a user interface Provide a degree of hardware independence Manage system memory Manage processing tasks Provide networking capability Control access to system resources Manage files
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User Interface User interface Command-based user interface
A function of the operating system that allows individuals to access and command the computer Command-based user interface A particular user interface that requires text commands be given to the computer to perform basic activities E.g., unix, DOS Graphical user interface (GUI) A user interface that uses pictures (icons) and menus displayed on the screen to send commands to the computer system E.g. Windows, MAC OS
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Systems Software Concepts
Hardware independence Operating system (OS) provides hardware independence for application software Application software interfaces with the operating system which interfaces with the hardware When the hardware is changed, the operating system is changed so that the application software is not required to be changed
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Software Concepts Memory management Virtual memory & paging
Multitasking Multithreading Timesharing
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Memory Management Memory management…
Controls how memory is accessed and maximizes available memory and storage Schematic
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Application Software OS
What is the price of TIBA35 (TIBA35$) Fetch TIBA35$ from hard disk, track 1, sector 7 TIBA35$
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Software Concepts Memory management Virtual memory & paging
Multitasking Multithreading Timesharing
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Virtual Memory & Paging
Memory that allocates space in secondary storage to supplement the immediate, functional memory capacity of RAM Paging A function of virtual memory allowing the computer to store currently needed pages in RAM while the rest of the pages wait in secondary storage Schematic
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Memory Disk Program 1 (a few pages) Program 2 (a few pages)
Operating system and system software Programs and other software Program 2 (a few pages) Program 3 (a few pages) Program 4 (a few pages) Program 5 (a few pages) Program 6 (a few pages) Other memory requirements
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Virtual Memory ‘Discussion’ (1)
An imaginary memory area supported by some operating systems (for example, Windows but not DOS) in conjunction with the hardware. You can think of virtual memory as an alternate set of memory addresses. Programs use these virtual addresses rather than real addresses to store instructions and data. When the program is actually executed, the virtual addresses are converted into real memory addresses. The purpose of virtual memory is to enlarge the address space, the set of addresses a program can utilize. For example, virtual memory
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Virtual Memory ‘Discussion’ (2)
might contain twice as many addresses as main memory. A program using all of virtual memory, therefore, would not be able to fit in main memory all at once. Nevertheless, the computer could execute such a program by copying into main memory those portions of the program needed at any given point during execution. To facilitate copying virtual memory into real memory, the operating system divides virtual memory into pages, each of which contains a fixed number of addresses. Each page is stored on a disk until it is needed. When the page is needed, the operating system copies it
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Virtual Memory ‘Discussion’ (3)
from disk to main memory, translating the virtual addresses into real addresses. The process of translating virtual addresses into real addresses is called mapping. The copying of virtual pages from disk to main memory is known as paging or swapping.
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Software Concepts Memory management Virtual memory & paging
Multitasking Multithreading Time-sharing
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Multitasking, Multithreading, Time-sharing
A processing activity that allows a user to run more than one application at the same time Multithreading A processing activity that is basically multitasking within a single application Time-sharing A processing activity that allows more than one person to use a computer system at the same time
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Software Concepts Network capability Access to system resources
Aids in connecting the computer to a network Access to system resources Provides security for unauthorized access File management Ensures that files in secondary storage are available when needed, and they are protected against unauthorized usage
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Utility Programs Utility programs…
Programs used to merge and sort sets of data, keep track of computer jobs being run, compress files of data before they are stored or transmitted over a network, and perform other important tasks
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Types of Application Software
Proprietary Designed to solve a unique and specific problem In-house Development of application software using the company’s resources Contract Developed for a particular company Off-the-shelf An existing software program that can be used without considerable changes expected
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Sources of Software Customized package
Blend of external and internal software development In-house customized Contract customization Schematic
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Off-the-shelf software
Application software Proprietary software Off-the-shelf software In-house developed Contract Standard package Customized package In-house customized Contract customization
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Examples
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Turbo Tax (Figure 4.6) Turbo Tax
Provides automated assistance for tax preparation and submission. (Figure 4.6) 24
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Quicken (Figure 4.7) Quicken
An off-the-shelf software package that provides assistance for standard check writing and personal accounting. (Figure 4.7) 25
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Word Processing (Figure 4.8) Word Processing
Provides assistance in formulating, formatting, and printing documents such as letters, memos, and papers. (Figure 4.8) 26
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Spreadsheet (Figure 4.9) Spreadsheet
Provides a wide range of built-in functions for statistical, financial, logical, database, graphics, and data and time calculations. (Figure 4.9) 27
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Database (Figure 4.10) Database
Stores, manipulates, and retrieves data. (Figure 4.10) 28
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Graphics Usually called Presentation Graphics Graphics Program
Helps make a presentation; develops brochures, illustrations, etc. Usually called Presentation Graphics
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On-Line Services (Figure 4.12)
On-Line Services Provide access to various information resources. (Figure 4.12) 30
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Software Suite Software Suite
Collection of personal productivity software such as word processor, spreadsheet, and database. 31
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Software Concepts - OLE
OLE = Object Linking and Embedding A software feature that allows you to copy text from one document to another or embed graphics from one program into another program or document Server Application The application that supplies objects you place into other applications Client application The application that accepts objects from other applications
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OLE Concepts Copy Link Embed
Copy data from one application and place it in another Link Changes made to the server object to automatically appear in all linked client objects Embed An object to become part of the client document Schematic
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Copy Link --- --- --- --- - --- --- --- -- -- -- - - - --- --- -
Graphics Program Server Application Client Application Word Processing Program Spreadsheet Program Server Application Team photo Actual vs. Budget Copy Team photo Link Actual vs. budget Project Management Program Server Application Chart Chart ==== == == == == == = === == == ==== ==== = Embed
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OLE ‘Discussion’ Abbreviation for Object Linking and Embedding, pronounced as separate letters or as oh-leh. OLE is a compound document standard developed by Microsoft Corporation. It enables you to create objects with one application and then link or embed them in a second application. Embedded objects retain their original format and links to the application that created them. Support for OLE is built into the Windows and Macintosh operating systems. A competing compound document standard developed jointly by IBM, Apple Computer, and other computer firms is called OpenDoc.
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Workgroup Application Software
Groupware Software that helps groups of people work together more efficiently and effectively Collaborative computing software Software that helps teams of people work together toward a common goal
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Enterprise Application Software
Software that benefits the entire organization Examples Accounts receivable Sales ordering Accounts payable Order entry Cash-flow analysis Check processing Manufacturing control Receiving General Ledger Retail Operations
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Example Integrated Supply Chain Management Software
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Enterprise Resource Planning (ERP)
A set of integrated programs that manage a company’s vital business operations for an entire multi-site, global organization Vendor examples SAP Baan Oracle SSA PeopleSoft Marcam Dun & Bradstreet QAD JD Edwards Ross Systems
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ERP ‘Discussion’ Short for enterprise resource planning, a business management system that integrates all facets of the business, including planning, manufacturing, sales, and marketing. As the ERP methodology has become more popular, software applications have emerged to help business managers implement ERP.
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Programming Languages
Coding schemes used to write both systems and application software
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Categories of Programming Languages (1)
Machine Language 1st generation programming language Considered a low-level language because it involves basic coding using the binary symbols 1 and 0 Assembly Language 2nd generation language Replaced binary digits with mnemonics (e.g., “ADD”) programmers could more easily understand
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Categories of Programming Languages (2)
Third Generation Languages Continued trend to more symbolic code (e.g. COBOL) Fourth Generation Languages (4GLs) Languages that are less procedural and even more English-like than third-generation languages (e.g. FOCUS)
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Categories of Programming Languages (3)
Query languages Used to ask the computer questions in English- like sentences Also known as database languages Structured query language (SQL) A standardized language often used to perform database queries and manipulations
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Object Oriented Languages (1)
Object-oriented languages (OOL) Languages that allow interaction of programming objects, including data elements and the actions that will be performed on them Note: OOP = object-oriented programming Encapsulation The process of grouping items into an object Polymorphism A process allowing the programmer to develop one routine or set of activities that will operate on multiple objects
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Object Oriented Languages (2)
Inheritance Property used to describe objects in a group of objects taking on characteristics of other objects in the same group or class of objects Reusable code The instruction code within an object that can be reused in different programs for a variety of applications Examples Smalltalk, C++, Java
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Visual Programming Languages
Languages that use a mouse, icons, or symbols on the screen and pull-down menus to develop programs Examples Visual Basic Visual C++ PC COBOL
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Fifth-Generation Languages
Combines rule-based code generation, component management, visual programming techniques, and reuse management Knowledge-based management An approach to the development of computer programs in which you do not tell a computer how to do a job, but what you want it to do
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Programming Languages: Terminology (1)
Language translator Systems software that converts a programmer’s source code into its equivalent in machine language Source code High-level program code written by the programmer Object code Another name for machine language code
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Programming Languages: Terminology (2)
Interpreter A language translator that translates one program statement at a time into machine code Program statement Interpreter Machine language statement Statement execution
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Programming Languages: Terminology (3)
Compiler A language translator that converts a complete program into machine language to produce a program that the computer can process in its entirety Schematic
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Step 1: Translate program
Computer program Compiler Machine language program Step 2: Execute program Machine language program Program execution
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End of Chapter 4 Chapter 5
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Organizing Data and Information
Chapter 5 Organizing Data and Information
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Data Data Database Database management system (DBMS)
A necessity for almost any enterprise to carry out its business. Consists of raw facts, and when organized may be transformed into information Database A collection of data organized to meet users’ needs Database management system (DBMS) A group of programs that manipulate the database and provide an interface between the database and the user of the database or other application programs
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DBMS ‘Discussion’ (1) A collection of programs that enables you to store, modify, and extract information from a database. There are many different types of DBMSs, ranging from small systems that run on personal computers to huge systems that run on mainframes. The following are examples of database applications: computerized library systems automated teller machines flight reservation systems computerized parts inventory systems From a technical standpoint, DBMSs can differ widely. The terms
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DBMS ‘Discussion’ (2) relational, network, flat, and hierarchical all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information. Requests for information from a database are made in the form of a query, which is a stylized question. For example, the query SELECT ALL WHERE NAME = "SMITH" AND AGE > 35 requests all records in which the NAME field is SMITH and the AGE
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DBMS ‘Discussion’ (3) field is greater than 35. The set of rules for constructing queries is known as a query language. Different DBMSs support different query languages, although there is a semi-standardized query language called SQL (structured query language). Sophisticated languages for managing database systems are called fourth-generation languages, or 4GLs for short. The information from a database can be presented in a variety of formats. Most DBMSs include a report writer program that enables you to output data in the form of a report. Many DBMSs also include
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DBMS ‘Discussion’ (4) a graphics component that enables you to output information in the form of graphs and charts.
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Hierarchy of Data Schematic
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Database Files Records Fields Characters (bytes)
Hierarchy of data Example Database Personel file Department file (Project database) Payroll file Files Johns Francine Buckley Bill Fiske Steven (Personnel file) Records (Record containing SSN, last name, first name, date of hire) Fiske Steven Fields Fiske (Last name field) Characters (bytes) (Letter ‘F’ in ASCII)
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Terminology Database File Record Field Character
A collection of integrated and related files File A collection of related records Record A collection of related fields Field A group of characters Character Basic building block of information, represented by a byte
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Data Entities, Attributes, and Keys
Entity A generalized class of people, places, or things (objects) for which data are collected, stored, and maintained E.g., Customer, Employee Attribute A characteristic of an entity; something the entity is identified by E.g., Customer name, Employee name Keys A field or set of fields in a record that is used to identify the record E.g, A field or set of fields that uniquely identifies the record
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Keys and Attributes Employee # Last name First name Hire date Dept. #
Johns Francine 257 Buckley Bill 650 Fiske Steven 1-5-85 598 Entities (records) Key field Attributes (fields)
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The Traditional Approach
Separate files are created and stored for each application program Schematic
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Inventory control programs Reports
Application programs Data Files Users Payroll Payroll programs Reports Invoicing Invoicing programs Reports Inventory control Inventory control programs Reports Management inquiries Management inquiries programs Reports
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Drawbacks Data redundancy Lack of data integrity
Duplication of data in separate files Lack of data integrity The degree to which the data in any one file is accurate Program-data dependence A situation in which program and data organized for one application are incompatible with programs and data organized differently for another application
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Database Approach The database approach…
A pool of related data is shared by multiple application programs Rather than having separate data files, each application uses a collection of data that is either joined or related in the database Schematic
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Applications programs
Payroll program Reports Payroll data Inventory data Invoicing Data Other data Inventory program Reports Database management system Invoicing program Reports Other programs Reports Database Interface Applications programs Users
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Advantages Improved strategic use of corporate data
Reduced data redundancy Improved data integrity Easier modification and updating Data and program independence Better access to data and information Standardization of data access A framework for program development Better overall protection of the data Shared data and information resources
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Disadvantages Relatively high cost of purchasing and operating a DBMS in a mainframe operating environment Increased cost of specialized staff Increased vulnerability
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Data Modeling and Database Models (1)
Planned data redundancy A way of organizing data in which the logical database design is altered so that certain data entities are combined Summary totals are carried in the data records rather than calculated from elemental data Some data attributes are repeated in more than one data entity to improve database performance
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Data Modeling and Database Models (2)
A map or diagram of entities and their relationships Enterprise data modeling Data modeling done at the level of the entire organization Entity-relationship (ER) diagrams A data model that uses basic graphical symbols to show the organization of and relationships between data
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Example: Entity Relationship (ER) Diagram for a Customer Ordering Database
Schematic
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Identification number Identification number
Last name Colour Attributes Entities First name Order Customer Product Name 1 N 1:N one-to-many relationship Identification number Identification number
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Hierarchical Database Model
A data model in which data are organized in a top-down, or inverted tree structure Schematic
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Project 1 Department A Department B Department C
Employee 1 Employee 2 Employee 3 Employee 4 Employee 5 Employee 6
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Network Data Model Network data model
An expansion of the hierarchical database model with an owner-member relationship in which a member may have many owners Project 1 Project 2 Department A Department B Department C
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Relational Data Model Relational data model
All data elements are placed in two- dimensional tables, called relations, that are the logical equivalent of files Schematic
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Data Table 1: Project Table Data Table 2: Department Table
Project Number Description Dept. Number 155 Payroll 257 498 Widgets 632 226 Sales manager 598 Dept. Number Dept. Name Manager SSN 257 Accounting 632 Manufacturing 598 Marketing Data Table 3: Manager Table SSN Last Name First Name Hire Date Dept. Number Johns Francine 257 Buckley Bill 650 Fiske Steven 1-5-85 598
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Relational Database Terminology
Selecting Data manipulation that eliminates rows according to certain criteria Projecting Data manipulation that eliminates columns in a table Joining Data manipulation that combines two or more tables Linked Relating tables in a relational database together
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Linking Data Tables to Answer an Inquiry
Schematic
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Project Number Description Dept. Number 155 Payroll 257 498 Widgets 632 226 Sales manager 598 Dept. Number Dept. Name Manager SSN 257 Accounting 632 Manufacturing 598 Marketing SSN Last Name First Name Hire Date Dept. Number Johns Francine 257 Buckley Bill 650 Fiske Steven 1-5-85 598
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Building and Modifying a Relational Database
Using Microsoft Access Screen snap
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Schemas and Subschemas
A description of the entire database Subschema A file that contains a description of a subset of the database and identifies which users can perform modifications on the data items in that subset Schematic
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DBMS Schema Subschema A Subschema B Subschema C User 1 User 2 User 3 User 4 User 5
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Schema ‘Discussion’ Pronounced skee-ma, the structure of a database system, described in a formal language supported by the database management system (DBMS). In a relational database, the schema defines the tables, the fields in each table, and the relationships between fields and tables. Schemas are generally stored in a data dictionary. Although a schema is defined in text database language, the term is often used to refer to a graphical depiction of the database structure.
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Data Definition Language
Data Definition Language (DDL) A collection of instructions and commands used to define and describe data and data relationships in a specific database Schematic
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SCHEMA DESCRIPTION SCHEMA NAME IS XXXX AUTHOR XXXX DATE XXXX FILE DESCRIPTION FILE NAME IS XXXX ASSIGN XXXX AREA DESCRIPTION AREA NAME IS XXXX RECORD DESCRIPTION RECORD NAME ISXXXX RECORD ID IS XXXX LOCATION MODE ISXXXX WITHIN XXX AREA FROM XXXX THRU XXXX SET DESCRIPTION SET NAME IS XXXX ORDER IS XXXX MODE IS XXXX MEMBER IS XXXX .
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Data Dictionary Data Dictionary
A detailed description of all data used in the database Schematic
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NORTHWESTERN MANUFACTURING
PREPARED BY: D. BORDWELL DATE: 04 AUGUST APPROVED BY: J. EDWARDS DATE: 13 OCTOBER VERSION: 3.1 PAGE: 1 OF 1 DATA ELEMENT NAME: PARTNO DESCRIPTION: INVENTORY PART NUMER OTHER NAMES: PTNO VALUE RANGE: 100 TO 5000 DATA TYPE: NUMERIC POSITIONS: 4 POSITIONS OR COLUMNS
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Data Dictionary Features
Provide a standard definition of terms and data elements Assist programmers in designing and writing programs Simplify database modification Reduce data redundancy Increase data reliability Faster program development Easier modification of data and information
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Logical and Physical Access Paths
Logical access path (LAP) Application requires information from the DBMS Physical access path (PAP) DBMS accesses a storage device to retrieve data Schematic
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Data on storage devices DBMS Management inquiries Other software
Physical access path (PAP) DBMS Logical access path (LAP) Management inquiries Other software Application programs
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Manipulating Data Concurrency control Data manipulation language (DML)
A method of dealing with a situation in which two or more people need to access the same record in a database at the same time Data manipulation language (DML) The commands that are used to manipulate the data in a database Structured query language (SQL) A standardized data manipulation language
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Structured Query Language (SQL)
“Invented” at IBM’s Almaden Research Centre (San Jose, CA) in the 1970s E.g., SELECT * FROM EMPLOYEE WHERE JOB_CLASSIFICATION = “C2” Select all (“*”) columns from the EMPLOYEE table in which the JOB_CLASSIFICATION field is equal to “C2”
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SQL ‘Discussion’ (1) Abbreviation of structured query language, and pronounced either see-kwell or as separate letters. SQL is a standardized query language for requesting information from a database. The original version called SEQUEL (structured English query language) was designed by an IBM research center in 1974 and SQL was first introduced as a commercial database system in 1979 by Oracle Corporation. Historically, SQL has been the favorite query language for database management systems running on minicomputers and mainframes.
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SQL ‘Discussion’ (2) Increasingly, however, SQL is being supported by PC database systems because it supports distributed databases (databases that are spread out over several computer systems). This enables several users on a local-area network to access the same database simultaneously. Although there are different dialects of SQL, it is nevertheless the closest thing to a standard query language that currently exists. In 1986, ANSI approved a rudimentary version of SQL as the official standard, but most versions of SQL since then have included many
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SQL ‘Discussion’ (3) extensions to the ANSI standard. In 1991, ANSI updated the standard. The new standard is known as SAG SQL.
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Database Output Screen snap
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Popular Database Management Systems for End Users
Microsoft Access 98 Lotus Approach 98 Inprise (formerly Borland) dBASE DBMS Selection Criteria Database size Number of concurrent users Performance Integration Features The vendor Cost
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Distributed Databases
A database in which the actual data may be spread across several smaller databases connected via telecommunications devices ‘Pretty’ picture
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Data Warehouse Data warehouse Data mart
A relational database management system designed specifically to support management decision making Current evolution of Decision Support Systems (DSSs) Data mart A subset of a data warehouse for small and medium- size businesses or departments within larger companies Schematic
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Hierarchical databases
Relational databases Hierarchical databases Network databases Flat files Spreadsheets Data extraction process Data cleanup process Data wharehouse End user access Query and analysis tools
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Designing a Customer Data Warehouse
Sharply define your goals and objectives before you build the warehouse Choose the software that best fits your goals Determine who/what should be in the database Develop a plan Measure results
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Data Mining Applications
The automated discovery of patterns and relationships in a data warehouse Data mining applications Market segmentation Customer queries Fraud detection Direct marketing Market basket analysis Trend analysis
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On-Line Analytical Processing (OLAP)
On-line analytic processing (OLAP) Access to multidimensional databases providing managerially useful display techniques Now used to store and deliver data warehouse information Data warehouse and OLAP Provides top-down, query-driven analysis Data mining Provides bottom-up, discovery-driven analysis
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Open Database Connectivity (ODBC)
A set of standards that ensures software written to comply with these standards can be used with any ODBC-compliant database Schematic
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dBASE ACCESS database Paradox database Lotus 1-2-3 spreadsheet
ODBC Import ACCESS database Paradox database ODBC Export ODBC Link Lotus 1-2-3 spreadsheet
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Object-Relational Database Management Systems (ORDBMS)
Object-relational database management system (ORDBMS) A DBMS capable of manipulating audio, video, and graphical data. Hypertext Users can search and manipulate alphanumeric data in an unstructured way Hypermedia Allows businesses to search and manipulate multimedia forms of data Spatial data technology Use of an object-relational database to store and access data according to the location it describes and to permit spatial queries and analysis
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End of Chapter 5 Chapter 6
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Telecommunications and Networks
Chapter 6 Telecommunications and Networks
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Communications Communications
The message (data and information) is communicated via the signal The transmission medium “carries” the signal Transmission medium Sender Receiver Signal
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Communications ‘Discussion’
The transmission of data from one computer to another, or from one device to another. A communications device, therefore, is any machine that assists data transmission. For example, modems, cables, and ports are all communications devices. Communications software refers to programs that make it possible to transmit data.
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Telecommunications Telecommunications Telecommunication medium
The electronic transmission of signals for communications, including such means as: Telephone Radio Television Telecommunication medium Anything that carries an electronic signal and interfaces between a sending device and a receiving device
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Communications and Telecommunications
In human speech, the sender transmits a signal through the transmission medium of the air In telecommunications, the sender transmits a signal through the transmission medium of a cable Schematic
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Data Communications Data communications
A specialized subset of telecommunications that refers to the electronic collection, processing, and distribution of data -- typically between computer system hardware devices
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Elements of a Telecommunications System
Telecommunication devices Relay signals between computer systems and transmission media Schematic
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Computer Network Computer network…
The communications media, devices, and software needed to connect two or more computer systems and/or devices Used to share hardware, programs, and databases across the organization Fosters teamwork, innovative ideas, and new business strategies
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Types of Telecommunications Media (1)
Twisted pair wire cable Insulated pairs of wires historically used in telephone service and to connect computer devices Coaxial cable Consists of an inner conductor wire surrounded by insulation, called the dielectric The dielectric is surrounded by a conductive shield, which is surrounded by a non- conductive jacket. Coaxial cable has better data transmission rate than twisted pair
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Twisted-pair ‘Discussion’
A type of cable that consists of two independently insulated wires twisted around one another. One wire carries the signal while the other wire is grounded and absorbs signal interference. Twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network (LAN) cable. Other types of cables used for LANs include coaxial cables and fiber optic cables.
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Coaxial Cable ‘Discussion’
A type of wire that consists of a centre wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference. Coaxial cabling is the primary type of cabling used by the cable television industry and is also widely used for computer networks. Although more expensive than standard telephone wire, it is much less susceptible to interference and can carry much more data. Because the cable television industry has already connected millions of homes with coaxial cable, many analysts believe that they are the best positioned to capitalize on the much-heralded information highway.
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Types of Telecommunications Media (2)
Fiber-optic Cable Many extremely thin strands of glass or plastic bound together in a sheathing which transmits signals with light beams Can be used for voice, data, and video
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Fiber Optic ‘Discussion’ (1)
A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves. Fiber optics has several advantages over traditional metal communications lines: Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data Fiber optic cables are less susceptible than metal cables to interference Fiber optic cables are much thinner and lighter than metal wires Data can be transmitted digitally (the natural form for computer data) rather than analogically.
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Fiber Optic ‘Discussion’ (2)
The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more fragile than wire and are difficult to split. Fiber optics is a particularly popular technology for local-area networks. In addition, telephone companies are steadily replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will employ fiber optics.
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Types of Telecommunications Media (3)
Microwave Communications Line-of-sight devices which must be placed in relatively high locations Microwave usage Information is converted to a microwave signal, sent through the air to a receiver, and recovered Pretty picture
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Types of Telecommunications Media (4)
Satellite transmission Communications satellites are relay stations that receive signals from one earth station and rebroadcast them to another They use microwave signals Pretty picture
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Types of Telecommunications Media (5)
Cellular transmission Signals from cells are transmitted to a receiver and integrated into the regular network Pretty picture
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Cellular ‘Discussion’
Refers to communications systems, especially the Advance Mobile Phone Service (AMPS), that divide a geographic region into sections, called cells. The purpose of this division is to make the most use out of a limited number of transmission frequencies. Each connection, or conversation, requires its own dedicated frequency, and the total number of available frequencies is about 1,000. To support more than 1,000 simultaneous conversations, cellular systems allocate a set number of frequencies for each cell. Two cells can use the same frequency for different conversations so long as the cells are not adjacent to each other. For digital communications, several competing cellular systems exist, including GSM and CDMA.
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Types of Telecommunications Media (6)
Infrared transmission Involves sending signals through the air via light waves Requires line-of-sight and short distances (a few hundred yards) Used to connect various computing devices such as handheld computers Sorry, no pretty picture!
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Terminology Analog Signal Digital Signal Modems
A continuous, curving signal Digital Signal A signal represented by bits Modems Devices that translate data from digital to analog and analog to digital
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Analog ‘Discussion’ (1)
Almost everything in the world can be described or represented in one of two forms: analog or digital. The principal feature of analog representations is that they are continuous. In contrast, digital representations consist of values measured at discrete intervals. Digital watches are called digital because they go from one value to the next without displaying all intermediate values. Consequently, they can display only a finite number of times of the day. In contrast, watches with hands are analog, because the hands move continuously around the clock face. As the minute hand goes
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Analog ‘Discussion’ (1)
around, it not only touches the numbers 1 through 12, but also the infinite number of points in between. Early attempts at building computers used analog techniques, but accuracy and reliability were not good enough. Today, almost all computers are digital.
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Digital ‘Discussion’ (1)
Describes any system based on discontinuous data or events. Computers are digital machines because at their most basic level they can distinguish between just two values, 0 and 1, or off and on. There is no simple way to represent all the values in between, such as All data that a computer processes must be encoded digitally, as a series of zeroes and ones. The opposite of digital is analog. A typical analog device is a clock in which the hands move continuously around the face. Such a clock is capable of indicating every possible time of day. In contrast, a
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Digital ‘Discussion’ (2)
digital clock is capable of representing only a finite number of times (every tenth of a second, for example). In general, humans experience the world analogically. Vision, for example, is an analog experience because we perceive infinitely smooth gradations of shapes and colors. Most analog events, however, can be simulated digitally. Photographs in newspapers, for instance, consist of an array of dots that are either black or white. From afar, the viewer does not see the dots (the digital form), but only lines and shading, which appear to be continuous. Although
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Digital ‘Discussion’ (3)
digital representations are approximations of analog events, they are useful because they are relatively easy to store and manipulate electronically. The trick is in converting from analog to digital, and back again. This is the principle behind compact discs (CDs). The music itself exists in an analog form, as waves in the air, but these sounds are then translated into a digital form that is encoded onto the disk. When you play a compact disc, the CD player reads the digital data, translates it back into its original analog form, and sends it to the
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Digital ‘Discussion’ (4)
amplifier and eventually the speakers. Internally, computers are digital because they consist of discrete units called bits that are either on or off. But by combining many bits in complex ways, computers simulate analog events. In one sense, this is what computer science is all about.
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How a Modem Works Modem Modulates a digital signal into an analog signal for transmission via analog medium, then demodulates the signal into digital for receiving Pretty picture
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Modem ‘Discussion’ (1) Acronym for modulator-demodulator. A modem is a device or program that enables a computer to transmit data over telephone lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms. Fortunately, there is one standard interface for connecting external modems to computers called RS-232. Consequently, any external modem can be attached to any computer that has an RS-232 port, which almost all personal computers have. There are also modems
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Modem ‘Discussion’ (2) that come as an expansion board that you can insert into a vacant expansion slot. These are sometimes called onboard or internal modems.
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Multiplexer Multiplexer
Allows several telecommunications signals to be transmitted over a single communications medium at the same time Pretty picture
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Communications link Multiplexor Front-end processor Host computer
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Multiplexor ‘Discussion’
A communications device that multiplexes (combines) several signals for transmission over a single medium. A demultiplexor completes the process by separating multiplexed signals from a transmission line. Frequently a multiplexor and demultiplexor are combined into a single device capable of processing both outgoing and incoming signals. A multiplexor is sometimes called a mux.
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Front-End Processor Front-end processor…
Special purpose computers that manage communication to and from a computer system Pretty picture
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Incoming and outgoing jobs
Front-end processor Main system Job 4
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Carriers and Services (1)
Organizations that take the responsibility of ensuring telecommunications can effectively take place between enterprises Common carriers Long-distance telephone companies Value-added carriers Companies that have developed private telecommunications systems and offer their services for a fee Switched lines Lines that use switching equipment to allow one transmission device to be connected to other transmission devices (e.g., standard telephone line) Dedicated line A line that provides constant connection between two points. No switching or dialing is needed
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Carriers and Services (2)
Private branch exchange (PBX) Communication system that can manage both voice and data transfer within a location (e.g. a building) and to outside lines Wide area telecommunication service (WATS) Billing method for heavy users of voice services Phone and dialing services Includes automatic number identification (a.k.a. caller ID) Integration of telephones and personal computers Access code screening Call priorities One number portability (use anywhere) Intelligent dialing (auto re-dial for a busy number)
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Carriers and Services (3)
ISDN ISDN = Integrated Services Digital Network Technology that uses existing common-carrier lines to simultaneously transmit voice, video, and image data in digital form Pretty picture
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Carriers and Services (4)
T1 carriers An expensive service developed by AT&T to increase the number of voice calls that could be handled through existing cables Digital subscriber lines (DSL) Uses existing phone wires going into today’s homes and businesses to provide transmission speeds exceeding 500 Kbps at a cost of $100 - $300 per month
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Networks and Distributed Processing
Centralized processing Data processing that occurs in a single location or facility Decentralized processing Data processing that occurs when devices are placed at various remote locations Distributed processing Data processing that occurs when computers are placed at remote locations but are connected to each other via telecommunications devices
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Network Concepts and Considerations
Network Topology A logical model that describes how networks are structured or configured Topologies… Ring (see chapter 1) Bus (see chapter 1) Star (see chapter 1) Hierarchical Hybrid
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Hierarchical Uses treelike structures with messages passed along the branches of the hierarchy Hybrid Network made up of various types of topologies
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Network Types Local area network (LAN) Wide area network (WAN)
Connects computer systems and devices in the same geographic area (can be Ring, Bus, Hierarchical, Star, Hybrid) Wide area network (WAN) Ties together large geographic regions using microwave and satellite transmission or telephone lines International network Links systems between countries
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Terminal-to-Host Connection
Applications and databases reside on the same host computer User interacts with the application using a “dumb terminal” Target PC “dumb terminal” Host computer
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File Server Connection
Applications and databases reside on the same host computer File server transfers data and programs to PCs on the network, where these target PCs perform most of the processing Target PC File downloaded to user File server Host computer
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Client/Server Connection
Applications and databases reside on specialized host computers Servers do most or all of the processing and transmit the results to the client Client Server Server Client Server
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Advantages & Disadvantages of Client/Server
Reduced cost potential Improved Performance Increased Security Disadvantages Increased cost potential Loss of control Complex multi-vendor environment
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Communications Software and Protocols (1)
Provides error checking, message formatting, communications logs, data security and privacy, and translation capabilities for networks Network operating system (NOS) Systems software that controls the computer systems and devices on a network and allows them to communicate with each other Network management software Enables a manager on a networked desktop to monitor the use of individual computers and shared hardware, scan for viruses, and ensure compliance with software licenses
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Communications Software and Protocols (2)
Rules that ensure communications among computers of different types and from different manufacturers.
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Communications Software and Protocols (3)
Open Systems Interconnection (OSI) Model Serves as a standard model for network architectures and is endorsed by the International Standards Committee Communication functions are represented in seven layers to promote the development of modular networks. Designed to permit communication among different computers from different operating systems Seven layers (see figure 6.20)
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Communications Software and Protocols (4)
TCP/IP TCP/IP = Transmission Control Protocol/Internet Protocol Standard originally developed by the U.S. government to link defense research agencies; it is the primary communication protocol of the Internet Systems Network Architecture (SNA) IBM communication protocol Ethernet Protocol standard developed forLANs using a bus topology X.400 and X.500 An international standard for message handling and network directories
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Bridges, Routers, Gateways and Switches
Connects two or more networks, with the same protocol, at the media control portions of the data link layer Router Operates at the network level of the OSI model and features more sophisticated addressing software than bridges. Can determine preferred paths Gateway Operates at or above the OSI transport layer and links LANs or networks that employ different architectures and use dissimilar protocols Switch Routes or switches data to its destination Schematic
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Machine #1 Machine #2 Machine #3 Gateway box Machine #4 Application
7 7 7 7 7 7 Presentation 6 6 6 6 6 6 Session 5 5 5 5 5 5 Router box Transport 4 4 4 4 4 4 Bridge box Network 3 3 3 3 3 3 3 3 Data link 2 2 2 2 2 2 2 2 2 2 Physical 1 1 1 1 1 1 1 1 1 1 Media
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Telecommunications Applications (1)
Linking personal computers to mainframe computers Download and upload information Voice mail Enables users to leave, receive, and store verbal messages for and from other users Electronic mail ( ) Enables a sender to connect a computer to a network, type messages, and send it to another person on the network
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Telecommunications Applications (2)
Electronic software distribution Involves installing software on a file server for users to share by signing onto the network and requesting that the software be downloaded onto their computers over a network Electronic document distribution Transporting documents -- such as sales reports, policy manuals, and advertising brochures -- over communications lines and networks Telecommuting Enables employees to work away from the office using personal computers and networks to communicate via electronic mail with other workers and to pick up and deliver results
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Telecommunications Applications (3)
Videoconferencing Allows participants to conduct long-distance meetings “face to face” while eliminating Pretty picture
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Telecommunications Applications (4)
Electronic Data Interchange (EDI) Uses network systems and follows standards and procedures that allow output from one system to be processed directly as input to other systems, without human intervention Pretty picture
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Third-party clearing house
EDI link Vendor Customer (a) EDI link EDI link Third-party clearing house Vendor Customer (b)
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Telecommunications Applications (5)
Public network services Services that give personal computer users access to vast databases and other services, usually for an initial fee plus usage fees Specialized and regional information services Specialized electronic bulletin boards and services targeting particular interests. Distance learning Use of telecommunications to extend the classroom
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End of Chapter 6 Chapter 7
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The Internet, Intranets, and Extranets
Chapter 7 The Internet, Intranets, and Extranets
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The Internet The internet Internet networks A network of networks
The internet transmits data from one computer (called a host) to another Internet networks Linked networks that work much the same way -- they pass data around in packets, each of which carries the addresses of its sender and receiver Schematic
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Internet ‘Discussion’ (1)
A global network connecting millions of computers. As of 1999, the Internet has more than 200 million users worldwide, and that number is growing rapidly. More than 100 countries are linked into exchanges of data, news and opinions. Unlike online services, which are centrally controlled, the Internet is decentralized by design. Each Internet computer, called a host, is independent. Its operators can choose which Internet services to use and which local services to make available to the global Internet community. Remarkably, this anarchy by design works exceedingly
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Internet ‘Discussion’ (2)
well. There are a variety of ways to access the Internet. Most online services, such as America Online, offer access to some Internet services. It is also possible to gain access through a commercial Internet Service Provider (ISP). Note: York University’s CCS (Computer and Communications Services) is an ISP.
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How the Internet Works Transport control protocol (TCP)
A protocol that operates at the transport layer and is used in combination with IP by most Internet applications Backbone An Internet high-speed, long distance communications links (like a bus; wire that connects nodes) Uniform resource locator (URL) An assigned address on the Internet for each computer E.g.,
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Domain Affiliations Domain Affiliations arts
cultural and entertainment activities com business organizations edu educational sites firm businesses and firms gov government sites info information service providers mil military sites nom individuals net networking organizations org organizations rec recreational activities store businesses offering goods for purchase web entities related to World Wide Web activities
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Access to the Internet LAN servers
Local servers can provide access to the Internet through normal connections (e.g., Ethernet) Serial line internet protocol (SLIP) and Point-to-point protocol (PPP) Communications protocol software that transmits packets over telephone lines, allowing dial-up access to the Internet Connection via an on-line service Examples are America Online and Microsoft Network. These services usually require sign-up procedures
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Three Ways to Access the Internet
Schematic
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Internet Service Providers
Internet service provider (ISP) Any company that provides individuals or companies with access to the Internet Thousands of providers including large communications companies Need an account with the ISP and software that links with TCP/IP
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ISP Examples Internet Service Provider Web Address
AT&T WorldNet Service Digex, Inc. GTE Internetworking IBM Internet Connection MCI Internet NetCom On-Line Communication Services PSINet, Inc. Sprint Internet Services Uunet Technologies, Inc.
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Internet Services E-mail Telnet FTP Usenet and newsgroups Chat rooms
Internet phone Internet videoconferencing Content streaming
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Selected Usenet Groups
alt.fan.addams.family alt.life.itself alt.pets alt.fan.bevis-n-butthead alt.autos.camaro alt.fan.leonardo-dicaprio alt.cloning alt.history alt.fan.u2 alt.music.blues alt.sports.baseball.cinci-red alt.music.zz-top alt.politics.socialism alt.sports.college.sec alt.sports.soccer.european.uk
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Internet Services Internet telephony Also called voice-over-IP (VOIP)
Technology that enables network managers to route phone calls and fax transmissions over the same network they use for data
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VOIP ‘Discussion’ Internet telephony is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls. For users who have free, or fixed-price, Internet access, Internet telephony software essentially provides free telephone calls anywhere in the world. To date, however, Internet telephony does not offer the same quality of telephone service as direct telephone connections. There are many Internet telephony applications available. Some, like CoolTalk and NetMeeting, come bundled with popular Web browsers. Others are stand-alone products. Internet telephony products are sometimes called IP telephony, Voice over the Internet (VOI) or Voice over IP (VOIP) products.
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Content Streaming Content streaming
A method for transferring multimedia files over the Internet so that the data stream of voice and pictures plays continuously, without a break, or very few of them It also enables users to browse large files in real time
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The World Wide Web World Wide Web
A collection of tens of thousands of independently- owned computers that work together as one in an Internet service
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WWW Terminology Home page Hypermedia Hypertext markup language (HTML)
The cover page for a Web site that has graphics, titles, coloured text, etc. Hypermedia Tools that connect the data on Web pages, allowing users to access topics in whatever order they wish Hypertext markup language (HTML) The standard page description language for Web pages
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Some Interesting Web Sites
Says who? Library of Congress PointCast In-Box Direct Online Career Center New York Times Project Gutenberg Sportsline USA White House MIT Lab for Computer Science The Wall Street Journal
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WWW Terminology Web browser Web page Applet
Software that creates a unique hypermedia-based menu on your computer screen and provides a graphical interface to the Web Web page A screen of information sent to a requesting user and presented through a browser Applet A small program embedded in Web pages
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HTML “The” language of WWW pages Need we say more!!!
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Search Engines Search engines
A search tool for the Web (like card catalogs in libraries) E.g., Altavista Excite Galaxy Hotbot Infoseek Lycos Webcrawler Yahoo!
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Java Java An object-oriented programming language
Developed by Sun Microsystems Based on C++ Allows small programs -- applets -- to be embedded within an HTML document
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Applets Applets are small java programs that are downloaded from the server to the local machine
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Push Technology Push technology E.g.,
Technology that enables users to automatically receive information over the Internet rather than searching for it using a browser Also called Webcasting E.g., PointCast InterMind
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Webcasting ‘Discussion’
Using the Internet, and the World Wide Web in particular, to broadcast information. Unlike typical surfing, which relies on a pull method of transferring Web pages, webcasting uses push technologies.
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Push ‘Discussion’ (1) In client/server applications, to send data to a client without the client requesting it. The World Wide Web is based on a pull technology where the client browser must request a Web page before it is sent. Broadcast media, on the other hand, are push technologies because they send information out regardless of whether anyone is tuned in. Increasingly, companies are using the Internet to deliver information push-style. One of the most successful examples of this is PointCast, which delivers customized news to users' desktops.
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Push ‘Discussion’ (2) Probably the oldest and most widely used push technology is . This is a push technology because you receive mail whether you ask for it or not -- that is, the sender pushes the message to the receiver.
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Business Use of the Web Uses:
Applications, , Product Display, Catalogs, Order placement Products people are likely to buy on the Web Software 77% Books 67% CDs 64% Computer hardware 63% Airline tickets 61% Magazine subscriptions 53% Concert/theater tickets 48% Flowers 45%
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Intranets and Extranets
An internal corporate network built using Internet and World Wide Web standards and products that allows employees of an organization to gain access to corporate information Extranet A network based on Web technologies that links selected resources of the intranet of a company with its customers, suppliers, or other business partners
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Intranet ‘Discussion’
A network based on TCP/IP protocols (an internet) belonging to an organization, usually a corporation, accessible only by the organization's members, employees, or others with authorization. An intranet's Web sites look and act just like any other Web sites, but the firewall surrounding an intranet fends off unauthorized access. Like the Internet itself, intranets are used to share information. Secure intranets are now the fastest-growing segment of the Internet because they are much less expensive to build and manage than private networks based on proprietary protocols.
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Extranet ‘Discussion’
A new buzzword that refers to an intranet that is partially accessible to authorized outsiders. Whereas an intranet resides behind a firewall and is accessible only to people who are members of the same company or organization, an extranet provides various levels of accessibility to outsiders. You can access an extranet only if you have a valid username and password, and your identity determines which parts of the extranet you can view. Extranets are becoming a very popular means for business partners to exchange information.
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Firewall Firewall… A device that sits between your internal network and the outside Internet and limits access into and out of your network based on your organization’s access policy
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Virtual Private Network (VPN)
A secure connection between two points across the Internet Tunneling The process by which VPNs transfer information by encapsulating traffic in IP packets and sending the packets over the Internet Schematic
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VPN ‘Discussion’ Short for virtual private network, a network that is constructed by using public wires to connect nodes. For example, there are a number of systems that enable you to create networks using the Internet as the medium for transporting data. These systems use encryption and other security mechanisms to ensure that only authorized users can access the network and that the data cannot be intercepted.
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Tunneling ‘Discussion’
A technology that enables one network to send its data via another network's connections. Tunneling works by encapsulating a network protocol within packets carried by the second network. For example, Microsoft's PPTP technology enables organizations to use the Internet to transmit data across a virtual private network (VPN). It does this by embedding its own network protocol within the TCP/IP packets carried by the Internet. (Note: PPTP = point-to-point tunneling protocol) Tunneling is also called encapsulation.
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Internet Issues Management issues Service bottlenecks
No centralized governing body for the Internet Service bottlenecks Phenomenal growth has left a service void Providers underestimating computing power needed Reconciling router addresses needed to transverse the network
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Privacy & Security Cryptography Encryption Digital Signature
The process of converting a message into a secret code and changing the encoded message back to regular text Encryption The original conversion of a message into a secret code Digital Signature An encryption technique used for online financial transactions
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Encryption software running on sending computer
Have a nice day… Encryption software running on sending computer E%$&:”}{|… Decryption software running on Receiving computer Have a nice day…
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Firewalls Firewalls Assured pipeline
A method of preventing unauthorized access between a company’s computers and the Internet (looks at the header of a packet) Assured pipeline An Internet security method that looks at the entire request for data and then determines whether the request is valid
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Firewall ‘Discussion’ (1)
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
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Firewall ‘Discussion’ (2)
There are several types of firewall techniques: Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing. Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation. Circuit-level gateway: Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking. Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.
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Firewall ‘Discussion’ (3)
In practice, many firewalls use two or more of these techniques in concert. A firewall is considered a first line of defense in protecting private information. For greater security, data can be encrypted.
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End of Chapter 7 Chapter 8
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Chapter 8 Transaction Processing, Electronic Commerce, and Enterprise Resource Planning Systems
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Sophistication & complexity of processing & analysis
TPS, MIS, DSS, and AI/ES Hierarchy: Information AI/ES Less More Less More DSS Sophistication & complexity of processing & analysis Decision support Input & output Routine MIS TPS Data More Less More Less
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Transactions Transactions… Transaction processing systems (TPS)
Basic business operations such as customer orders, purchase orders, receipts, time cards, invoices, and payroll checks in an organization Transaction processing systems (TPS) Perform routine operations and serve as a foundation for other systems
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Batch vs. On-Line Transaction Processing
Two types of TPS: Batch processing A system whereby business transactions are accumulated over a period of time and prepared for processing as a single unit or batch On-line transaction processing (OLTP) A system whereby each transaction is processed immediately, without the delay of accumulating transactions into a batch
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Data entry of accumulated transactions
Batch Schematic Data entry of accumulated transactions Input (batched) Output
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On-line Schematic Immediate processing of each transaction Output
Terminal Terminal Terminal Output Immediate processing of each transaction Terminal Terminal Terminal
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Applications software
Integration of TPSs Schematic [ ]x n = Applications software People
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Objectives of TPS Process data generated by and about transactions
Maintain a high degree of accuracy Ensure data and information integrity and accuracy Produce timely documents and reports Increase labour efficiency Help provide increased and enhanced service Help build and maintain customer loyalty Achieve competitive advantage
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Simplified Overview of a Transaction Processing System
Schematic
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Data entry & input Documents & reports Processing Database Documents:
pick list cheques to vendors receiving notices paycheques Operational reports: finished product inventory status raw materials; packing materials; spare parts; inventory status Internally generated transactions: shipped orders purchase orders employee time cards Externally generated transactions: customer orders vendor invoices customer payments Database Database update: customer orders inventory purchase orders customers suppliers
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Data Processing Activities Common to TPSs
A transaction processing cycle Data collection Data editing Data correction Data manipulation Data storage Document production Schematic
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Original data Data collection Data edit Data manipulation Data correction Data storage Document production
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Source Data Automation
The process of capturing data at its source with minimal manual effort Data are entered directly into the computer
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Point-of-Sale Transaction Processing System
Customer’s receipt Inventory database Management information system Exception report UPC and quantity Point-of-sale transaction processing system UPC Scanner Quantity, Date, time Item, quantity, date, time, price Purchases database UPC Price Item database
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Control and Management Issues
Business resumption planning The process of anticipating and providing for disasters. Disaster recovery The implementation of the business resumption plan. Transaction processing system audit An examination of the TPS in an attempt to answer three basic questions Does the system meet the business need? What procedures and controls have been established? Are the procedures and controls being properly used?
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Traditional TPS – Order Processing
Processing an order from entry to delivery, including traditional accounting transactions Schematic
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Finished product inventory
Customer Invoice Products Customer order in person or via mail, phone, EDI, internet Order entry/ sales configuration Inventory status Orders Planned shipments Finished product inventory Shipment planning Routing Pick list Planned shipments & routes Shipment execution Scheduling Shipped orders Invoicing
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Data Flow Diagram of an Order Entry System
Schematic
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2. Verify product numbers & stock on hand
Inventory D1 Products/prices D2 Customer payment history Product numbers, inventory levels Products, price information Credit status 2. Verify product numbers & stock on hand Open orders 1. Collect order info 3. Authorize credit Orders Orders D3 New orders Rejected, partly filled orders Back orders Back orders 4. Notify customer D4 Back orders Customer Customer notification Rejected orders D5 Rejected orders
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Order Processing Support Systems - Sales Configuration
Ensures that products and services ordered are sufficient to accomplish customer’s objectives and will work well together
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Order Processing Support Systems - Shipment Planning
A system that determines which open orders will be filled and from which location they will be shipped E.g., (from Figure 8.9) LOC LINK ITEM NUMBER DESCRIPTION ORDERED SHIPPED BO 8 105 10 L1L16028 20 S8276 30 S8279 40 FASENTING TOOL STAPLE ¾ INCH STAPLE 1 INCH SHIPPING CHARGE 3 15 EACH CASE 12
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Order Processing Support Systems - Shipment Execution
A system that coordinates the outflow of all products and goods from the organization, with the objective of delivering quality products on time to customers
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Order Processing Support Systems - Inventory Control
A system that updates the computerized inventory records to reflect the exact quantity on hand of each stock keeping unit Status reports Summarize all inventory items in stock, or shipped over a specified period of time E.g., see Figure 8.10
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Order Processing Support Systems - Invoicing
Generates customer invoices based on records received from the shipment execution TPS E.g., see Figure 8.11
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Order Processing Support Systems - Customer Interaction System
A system that monitors and tracks each customer interaction with the company
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Customer interaction system
Request for proposal Sale Problem, idea, request for information Other contacts Customer interaction system Market research Product development Sales Quality control Marketing
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Order Processing Support Systems - Routing and Scheduling
A system that determines the best way to get goods and products from one location to another Scheduling A system that determines the best time to deliver goods and services
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Purchasing System Schematic
469
Purchase order processing
Raw materials Packing materials Spare parts Inventory control Inventory control status report Purchase order request Employees Purchase order processing Purchase order Purchase order Receiving Supplier Material Receiving notice Invoice Accounts payable Cheque
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Purchasing System Inventory control Purchase order (P.O.) processing
Maintains stock of items such as raw materials, packing materials, spare parts, and supplies Purchase order (P.O.) processing A system that helps purchasing department complete transactions quickly and efficiently Receiving A system that creates a record of expected and actual receipts Reconciles purchase orders with what is actually received Accounts payable A system that increases an organization’s control over purchasing, improves cash flow increases profitability, and provides more effective management of current liabilities
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P.O. Example (Click to view)
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Accounting System Accounting systems Consist of… Budget
Accounts receivable Accounts payable Payroll Asset management General ledger
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Accounts Payable Example
(Click to view)
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Financial Systems Schematic
477
Customer Asset management Cost of assets Payments Accounts payable Accounts receivable Amounts owed by customers Amounts paid by customers Amounts owed by company Amounts paid by company Payroll Labour costs General ledger Asset depreciation Paycheques Expense transactions Time cards Customer Budget
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Financial Systems - Accounts Receivable
A system that manages the cash flow of the company by keeping track of the money owed the company on charges for goods sold and services performed
479
‘Statement of Account’ Example
(Click to view)
481
Financial Systems – Accounts Receivable
Accounts receivable aging report Tells managers what bills are overdue, either customer by customer or in a summary format
482
‘Aging Report’ Example
(Click to view)
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Financial Systems - Payroll
Generates payroll checks and stubs, as well as W-2 statements at the end of the year for tax purposes
485
Financial Systems - Payroll
Payroll journal Helps managers monitor total payroll costs for an organization and the impact of those costs on cash flow
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Financial Systems - Asset Management
Asset management transaction processing system A system that controls investments in capital equipment and manages depreciation for maximum tax benefits
487
Financial Systems - General Ledger
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Electronic Commerce (E-commerce)
Business-to-business problems Inadequate models Integrating with existing systems Improving relationships with suppliers, customers, distributors. Consumer problems Wait for images to download Security of credit information Figuring out the ordering process Currently a small part of all commerce
489
Five Stage Model of E-Commerce
The stages consumers experience in the sales life cycle Schematic
490
2. Selection & negotiation 4. Product & service delivery
Buyer Electronic distribution Traditional delivery 1. Search and Identify 5. After sales service 2. Selection & negotiation 4. Product & service delivery 3. Purchasing
491
Buying Over the Internet
Prepare list of items needed Log on to internet Access supplier’s home page Browse supplier’s catalog Input sent to supplier’s order entry system Place order Review response to request for quotation Fill out request for quotation form Pick items
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Forecasted Volume of E-Commerce
Mode 1997 2000 Consumer $0.5 billion $7 billion Business $8.0 billion $66 billion
493
Purchasing Products and Services Electronically
Establish credit with suppliers Secure E-commerce transactions Secure financial transaction (SFT) SET = “secure electronic transaction” CyberCash
494
SET ‘Discussion’ (1) Short for Secure Electronic Transaction, a new standard that will enable secure credit card transactions on the Internet. SET has been endorsed by virtually all the major players in the electronic commerce arena, including Microsoft, Netscape, Visa, and Mastercard. By employing digital signatures, SET will enable merchants to verify that buyers are who they claim to be. And it will protect buyers by providing a mechanism for their credit card number to be transferred directly to the credit card issuer for verification and billing without
495
SET ‘Discussion’ (2) the merchant being able to see the number.
The first applications based on SET are expected appeared in 1998.
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Enterprise Resource Planning (ERP)
Real-time monitoring of business functions Advantages Eliminate costly, inflexible legacy systems Provide improved work processes Provide access to data for operational decision making Upgrading technology infrastrucutre Disadvantages Time consuming, difficult, expensive to implement Make radical changes in how a company operates Lack of vendor responsiveness in light of high demand
497
ERP Examples Software Vendor Name of Product Avalon Software
Avalon CIM qad.inc MRG/PRO Oracle Oracle Manufacturing SAP America SAP R/3 Baan Triton PeopleSoft J.D. Edwards World
498
Example of an ERP System - SAP/R3
Clients in the SAP system Application servers in the SAP system Business application programming interfaces (BAPIs) Database server in the SAP systems Objects in the SAP system Repository Tables
499
SAP Three-Tier Client/Server Architecture
Database server Application servers Client desktop computers
500
Business Application Programming Interface (BAPI)
Business processes Standard request for data or processing Standard results BAPI (public interface) Results consistent with current version of SAP software Request for data or processing consistent with current version of SAP software SAP software
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End of Chapter 8 Chapter 9
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Management Information Systems
Chapter 9 Management Information Systems
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Management Information Systems (MIS)
Management information system (MIS) An MIS provides managers with information and support for effective decision making, and provides feedback on daily operations Output, or reports, are usually generated through accumulation of transaction processing data Each MIS is an integrated collection of subsystems, which are typically organized along functional lines within an organization
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Sources of Management Information
Schematic
505
Databases of external data Corporate intranet
Employees Corporate databases of internal data Databases of external data Corporate intranet Decision support systems Databases of valid transactions Application databases Business transactions Transaction processing systems Management information systems Executive support systems Operational databases Expert systems Drill-down reports Exception reports Demand reports Key-indicator reports Input and error list Scheduled reports
506
Outputs of a Management Information System
Scheduled reports Produced periodically, or on a schedule (daily, weekly, monthly) Key-indicator report Summarizes the previous day’s critical activities Typically available at the beginning of each day Demand report Gives certain information at a manager’s request Exception report Automatically produced when a situation is unusual or requires management action
507
Scheduled Report Example
Daily Sales Detail Report Prepared: 08/10/xx Order # Customer ID Sales Rep ID Ship Date Quantity Item # Amount P12453 C89321 CAR 08/12/96 144 P1234 $3,214 288 P3214 $5,660 C03214 GWA 08/13/96 12 P4902 $1,224 P12455 C52313 SAK 24 P4012 $2,448 P12456 C34123 JMW 08J/13/96 $720
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Key Indicator Report Example
Daily Sales Key Indicator Report This Month Last Month Last Year Total Orders Month to Date $1,808 $1,694 $1,014 Forecasted Sales for the Month $2,406 $2,224 $2,608
509
Daily Sales by Sales Rep Summary Report
Demand Report Example Daily Sales by Sales Rep Summary Report Prepared: 08/10/xx Sales Rep ID Amount CAR $42,345 GWA $38,950 SAK $22,100 JWN $12,350
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Exception Report Example
Daily Sales Exception Report – ORDERS OVER $10,000 Prepared: 08/10/xx Order # Customer ID Sales Rep ID Ship Date Quantity Item # Amount P12453 C89321 CAR 08/12/96 144 P1234 $13,214 288 P3214 $15,660 C03214 GWA 08/13/96 12 P4902 $11,224 …
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Outputs of a Management Information System
Earnings by Quarter (Millions) Actual Forecast Variance 2ND Qtr 1999 $12.6 $11.8 6.8% 1st Qtr 1999 $10.8 $10.7 0.9% 4th Qtr 1998 $14.3 $14.5 -1.4% 3rd Qtr 1998 $12.8 $13.3 -3.0% Drill Down Reports Provide detailed data about a situation. Etc. See Figure 9.2
512
Characteristics of a Management Information System
Provides reports with fixed and standard formats Hard-copy and soft-copy reports Uses internal data stored in the computer system End users can develop custom reports Requires formal requests from users
513
Management Information Systems for Competitive Advantage
Provides support to managers as they work to achieve corporate goals Enables managers to compare results to established company goals and identify problem areas and opportunities for improvement
514
MIS and Web Technology Data may be made available from management information systems on a company’s intranet Employees can use browsers and their PC to gain access to the data
515
Functional Aspects MIS is an integrated collection of functional information systems, each supporting particular functional areas. Schematic
516
Figure 9.3 Internet An Organization’s MIS Financial MIS
Business transactions Databases of valid transactions Drill down reports Accounting MIS Transaction processing systems Exception reports Demand reports Key-indicator reports Marketing MIS Scheduled reports Business transactions Databases of external data Human Resources MIS Etc. Extranet Etc. Figure 9.3
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Financial MIS Provides financial information to all financial managers within an organization. Schematic
518
Financial MIS Figure 9.3 Financial DSS Business transactions
Databases of internal data Databases of external data Financial DSS Business transactions Databases of valid transactions for each TPS Financial applications databases Transaction processing systems Financial MIS Business transactions Operational databases Financial statements Financial ES Uses and management of funds Internet or Extranet Financial statistics for control Business transactions Customers, Suppliers Figure 9.3
519
Inputs to the Financial Information System
Strategic plan or corporate policies Contains major financial objectives and often projects financial needs. Transaction processing system (TPS) Important financial information collected from almost every TPS - payroll, inventory control, order processing, accounts payable, accounts receivable, general ledger. External sources Annual reports and financial statements of competitors and general news items.
520
Financial MIS Subsystems and Outputs
Financial subsystems Profit/loss and cost systems Auditing Internal auditing External auditing Uses and management of funds
521
Manufacturing MIS Schematic
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Manufacturing MIS Figure 9.6 Manufacturing DSS Business transactions
Databases of internal data Databases of external data Manufacturing DSS Business transactions Databases of valid transactions for each TPS Manufacturing applications databases Transaction processing systems Manufacturing MIS Business transactions Operational databases Quality control reports Manufacturing ES Process control reports Internet or Extranet JIT reports MRP reports Production schedule CAD output Business transactions Customers, Suppliers Figure 9.6
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Inputs to the Manufacturing MIS
Strategic plan or corporate policies. The TPS: Order processing Inventory data Receiving and inspecting data Personnel data Production process External sources
524
Manufacturing MIS Subsystems and Outputs
Design and engineering Master production scheduling Inventory control Manufacturing resource planning Just-in-time inventory and manufacturing Process control Computer-integrated manufacturing (CIM) Quality control and testing
525
Marketing MIS Supports managerial activities in product development, distribution, pricing decisions, and promotional effectiveness Schematic
526
Marketing MIS Figure 9.9 Manufacturing DSS
Databases of internal data Databases of external data Manufacturing DSS Databases of valid transactions for each TPS Marketing applications databases Transaction processing systems Marketing MIS Business transactions Sales by customer Operational databases Manufacturing ES Sales by salesperson Sales by product Pricing report Total service calls Customer satisfaction Figure 9.9
527
Inputs to Marketing MIS
Strategic plan and corporate policies The TPS External sources: The competition The market
528
Marketing MIS Subsystems and Outputs
Marketing research Product development Promotion and advertising Product pricing
529
Human Resource MIS Concerned with all of the activities related to employees and potential employees of the organization
530
Human Resource MIS Figure 9.12 Manufacturing DSS
Databases of internal data Databases of external data Manufacturing DSS Databases of valid transactions for each TPS Human resource applications databases Transaction processing systems Human Resource MIS Business transactions Benefit reports Operational databases Manufacturing ES Salary surveys Scheduling reports Training test scores Job applicant profiles Needs and planning reports Figure 9.12
531
Inputs to the Human Resource MIS
Strategic plan or corporate policies The TPS: Payroll data Order processing data Personnel data External sources
532
Human Resource MIS Subsystems and Outputs
Human resource planning Personnel selection and recruiting Training and skills inventory Scheduling and job placement Wage and salary administration
533
Other MISs Accounting MISs Geographic information systems (GISs)
Provides aggregated information on accounts payable, accounts receivable, payroll, and other applications. Geographic information systems (GISs) Enables managers to pair pre-drawn maps or map outlines with tabular data to describe aspects of a particular geographic region.
534
End of Chapter 9 Chapter 10
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Decision Support Systems
Chapter 10 Decision Support Systems
536
Decision Support Systems
Decision support systems (DSS) Offer potential to assist in solving both semi- structured and unstructured problems
537
Decision Making as a Component of Problem Solving
Intelligence Decision making Design Problem solving Choice Implementation Monitoring
538
Solution Types Optimization model Satisficing model Heuristics
Finding the best solution Satisficing model Finding a good -- but not necessarily the best -- solution to a problem Heuristics Commonly accepted guidelines or procedures that usually find a good solution
539
Problem Solving Factors
Multiple decision objectives Increased alternatives Increased competition The need for creativity Social and political actions International aspects Technology Time compression
540
Characteristics of a DSS (1)
Handles large amounts of data from different sources Provides report and presentation flexibility Offers both textual and graphical orientation
541
Characteristics of a DSS (2)
Supports drill down analysis Performs complex, sophisticated analysis and comparisons using advanced software packages Supports optimization, satisficing, and heuristic approaches
542
Characteristics of a DSS (3)
Performs different types of analyses “What-if” analysis Makes hypothetical changes to problem and observes impact on the results Simulation Duplicates features of a real system Goal-seeking analysis Determines problem data required for a given result
543
Goal Seeking Example You know the desired result
You want to know the required input(s) Example: Microsoft Excel’s “Goal Seek” and “Solver” functions
544
Excel demo
545
Capabilities of a DSS (1)
Supports Problem solving phases Different decision frequencies Merge with another company? How many widgets should I order? low high Frequency
546
Capabilities of a DSS (2)
Highly structured problems Straightforward problems, requiring known facts and relationships. Semi-structured or unstructured problems Complex problems wherein relationships among data are not always clear, the data may be in a variety of formats, and are often difficult to manipulate or obtain
547
Decision Making Levels
Strategic Tactical Operational Strategic-level managers involved with long-term decisions Operational-level managers involved with daily decisions High Low Decision Frequency
548
Integration of TPS, MIS, and DSS
In many organizations they are integrated through a common database Separation of DSS transactions in the database from TPS and MIS transactions may be important for performance reasons
549
Web-Based Decision Support Systems
Decision support system software provides business intelligence through web browser clients that access databases either through the Internet or a corporate intranet
550
Components of a DSS Model management software (MMS) Model base
Coordinates the use of models in the DSS Model base Provides decision makers with access to a variety of models Dialogue manager Allows decision makers to easily access and manipulate the DSS
551
Database Model base DBMS MMS External databases
Access to the internet, networks, and other computer systems External database access Dialogue manager
552
Model Base Model Base Models
Provides decision makers with access to a variety of models and assists them in decision making Models Financial models Statistical analysis models Graphical models Project management models
553
Advantages and Disadvantages of Modeling
Less expensive than custom approaches or real systems. Faster to construct than real systems Less risky than real systems Provides learning experience (trial and error) Future projections are possible Can test assumptions Disadvantages Assumptions about reality may be incorrect Accuracy of predications often unreliable Requires abstract thinking
554
Group Decision Support System
Group Decision Support System (GDSS) Contains most of the elements of DSS plus software to provide effective support in group decision-making settings
555
External database access
Databases Model base GDSS processor GDSS software External databases Access to the internet and corporate intranet, networks, and other computer system Dialogue manager External database access Users
556
Characteristics of a GDSS (1)
Special design Ease of use Flexibility Decision-making support Delphi approach (decision makers are geographically dispersed) Brainstorming Group consensus Nominal group technique
557
Characteristics of a GDSS (2)
Anonymous input Reduction of negative group behaviour Parallel communication Automated record keeping Cost, control, complexity factors
558
Group Results Matrix
559
Components of a GDSS and GDSS Software
Database Model base Dialogue manager Communication capability Special software (also called GroupWare) E.g., Lotus Notes people located around the world work on the same project, documents, and files, efficiently and at the same time
560
GDSS Alternatives high Local area decision network
Wide area decision network Decision frequency Decision room Teleconferencing low close distant Location of group members
561
Decision Room Decision Room
For decision makers located in the same geographic area or building Use of computing devices, special software, networking capabilities, display equipment, and a session leader Collect, coordinate, and feed back organized information to help a group make a decision Combines face-to-face verbal interaction with technology-aided formalization
563
Wide Area Decision Network
Characteristics Location of group members is distant Decision frequency is high Virtual workgroups Groups of workers located around the world working on common problems via a GDSS
564
Executive Support System
Characteristics A specialized DSS that includes all the hardware, software, data, procedures, and people used to assist senior-level executives within the organization Board of directors President Function area vice presidents Function area managers
565
Characteristics of ESSs
Tailored to individual executives Easy to use Drill down capabilities Support the need for external data Help with situations with high degree of uncertainty Futures orientation (predictions, forecasting) Linked with value-added business processes
566
Capabilities of an ESS Support for defining overall vision
strategic planning strategic organizing and staffing strategic control crisis management
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End of Chapter 10 Chapter 11
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Artificial Intelligence and Expert Systems
Chapter 11 Artificial Intelligence and Expert Systems
569
Overview of Artificial Intelligence (1)
Artificial intelligence (AI) Computers with the ability to mimic or duplicate the functions of the human brain Artificial intelligence systems The people, procedures, hardware, software, data, and knowledge needed to develop computer systems and machines that demonstrate the characteristics of intelligence
570
Overview of Artificial Intelligence (2)
Intelligent behaviour Learn from experience Apply knowledge acquired from experience Handle complex situations Solve problems when important information is missing Determine what is important React quickly and correctly to a new situation Understand visual images Process and manipulate symbols Be creative and imaginative Use heuristics
571
Major Branches of AI (1) Perceptive system Vision system Robotics
A system that approximates the way a human sees, hears, and feels objects Vision system Capture, store, and manipulate visual images and pictures Robotics Mechanical and computer devices that perform tedious tasks with high precision Expert system Stores knowledge and makes inferences
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Major Branches of AI (2) Learning system Natural language processing
Computer changes how it functions or reacts to situations based on feedback Natural language processing Computers understand and react to statements and commands made in a “natural” language, such as English Neural network Computer system that can act like or simulate the functioning of the human brain Schematic
573
Artificial intelligence
Vision systems Learning systems Robotics Expert systems Neural networks Natural language processing
574
Artificial Intelligence (1)
From Chapter 1 Artificial Intelligence (1) The branch of computer science concerned with making computers behave like humans. The term was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology. Artificial intelligence includes games playing: programming computers to play games such as chess and checkers expert systems : programming computers to make decisions in real-life situations (for example, some expert systems help doctors diagnose diseases based on symptoms) natural language : programming computers to understand natural human languages
575
Artificial Intelligence (2)
From Chapter 1 Artificial Intelligence (2) neural networks : Systems that simulate intelligence by attempting to reproduce the types of physical connections that occur in animal brains robotics : programming computers to see and hear and react to other sensory stimuli Currently, no computers exhibit full artificial intelligence (that is, are able to simulate human behavior). The greatest advances have occurred in the field of games playing. The best computer chess programs are now capable of beating humans. In May, 1997, an IBM super-computer called Deep Blue defeated world chess champion
576
Artificial Intelligence (3)
From Chapter 1 Artificial Intelligence (3) Gary Kasparov in a chess match. In the area of robotics, computers are now widely used in assembly plants, but they are capable only of very limited tasks. Robots have great difficulty identifying objects based on appearance or feel, and they still move and handle objects clumsily. Natural-language processing offers the greatest potential rewards because it would allow people to interact with computers without needing any specialized knowledge. You could simply walk up to a
577
Artificial Intelligence (4)
From Chapter 1 Artificial Intelligence (4) computer and talk to it. Unfortunately, programming computers to understand natural languages has proved to be more difficult than originally thought. Some rudimentary translation systems that translate from one human language to another are in existence, but they are not nearly as good as human translators. There are also voice recognition systems that can convert spoken sounds into written words, but they do not understand what they are writing; they simply take dictation. Even these systems are quite limited -- you must speak slowly and distinctly.
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Artificial Intelligence (5)
From Chapter 1 Artificial Intelligence (5) In the early 1980s, expert systems were believed to represent the future of artificial intelligence and of computers in general. To date, however, they have not lived up to expectations. Many expert systems help human experts in such fields as medicine and engineering, but they are very expensive to produce and are helpful only in special situations. Today, the hottest area of artificial intelligence is neural networks, which are proving successful in a number of disciplines such as voice recognition and natural-language processing.
579
Artificial Intelligence (6)
From Chapter 1 Artificial Intelligence (6) There are several programming languages that are known as AI languages because they are used almost exclusively for AI applications. The two most common are LISP and Prolog.
580
Overview of Expert Systems
Can… Explain their reasoning or suggested decisions Display intelligent behavior Draw conclusions from complex relationships Provide portable knowledge Expert system shell A collection of software packages and tools used to develop expert systems
581
Limitations of Expert Systems
Not widely used or tested Limited to relatively narrow problems Cannot readily deal with “mixed” knowledge Possibility of error Cannot refine own knowledge base Difficult to maintain May have high development costs Raise legal and ethical concerns
582
Capabilities of Expert Systems
Strategic goal setting Explore impact of strategic goals Planning Impact of plans on resources Integrate general design principles and manufacturing limitations Design Decision making Provide advise on decisions Quality control and monitoring Monitor quality and assist in finding solutions Diagnosis Look for causes and suggest solutions
583
When to Use an Expert System (1)
Provide a high potential payoff or significantly reduced downside risk Capture and preserve irreplaceable human expertise Provide expertise needed at a number of locations at the same time or in a hostile environment that is dangerous to human health
584
When to Use an Expert System (2)
Provide expertise that is expensive or rare Develop a solution faster than human experts can Provide expertise needed for training and development to share the wisdom of human experts with a large number of people
585
Components of an Expert System (1)
Knowledge base Stores all relevant information, data, rules, cases, and relationships used by the expert system Inference engine Seeks information and relationships from the knowledge base and provides answers, predictions, and suggestions in the way a human expert would Rule A conditional statement that links given conditions to actions or outcomes
586
Components of an Expert System (2)
Fuzzy logic A specialty research area in computer science that allows shades of gray and does not require everything to be simply yes/no, or true/false Backward chaining A method of reasoning that starts with conclusions and works backward to the supporting facts Forward chaining A method of reasoning that starts with the facts and works forward to the conclusions Schematic
587
Knowledge base acquisition facility
Explanation facility Inference engine Knowledge base Knowledge base acquisition facility User interface Experts User
588
Rules for a Credit Application
Mortgage application for a loan for $100,000 to $200,000 If there are no previous credits problems, and If month net income is greater than 4x monthly loan payment, and If down payment is 15% of total value of property, and If net income of borrower is > $25,000, and If employment is > 3 years at same company Then accept the applications Else check other credit rules
589
Explanation Facility Explanation facility
A part of the expert system that allows a user or decision maker to understand how the expert system arrived at certain conclusions or results
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Knowledge Acquisition Facility
Provides a convenient and efficient means of capturing and storing all components of the knowledge base Knowledge base Knowledge acquisition facility Joe Expert
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Expert Systems Development
Determining requirements Identifying experts Domain The area of knowledge addressed by the expert system. Construct expert system components Implementing results Maintaining and reviewing system
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Participants in Expert Systems Development and Use
Domain expert The individual or group whose expertise and knowledge is captured for use in an expert system Knowledge user The individual or group who uses and benefits from the expert system Knowledge engineer Someone trained or experienced in the design, development, implementation, and maintenance of an expert system Schematic
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Expert system Knowledge engineer Domain expert Knowledge user
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Evolution of Expert Systems Software
Expert system shell Collection of software packages & tools to design, develop, implement, and maintain expert systems high Expert system shells Special and 4th generation languages Ease of use Traditional programming languages low Before s s
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Advantages of Expert Systems
Easy to develop and modify The use of satisficing The use of heuristics Development by knowledge engineers and users
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Expert Systems Development Alternatives
high Develop from scratch Develop from shell Development costs Use existing package low low high Time to develop expert system
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Applications of Expert Systems and Artificial Intelligence
Credit granting Information management and retrieval AI and expert systems embedded in products Plant layout Hospitals and medical facilities Help desks and assistance Employee performance evaluation Loan analysis Virus detection Repair and maintenance Shipping Marketing Warehouse optimization
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End of Chapter 11 Chapter 12
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Chapter 12 Systems Development
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Overview of Systems Development
Participants Initiating systems development Information systems planning Establishing objectives for systems development Systems development and the Internet Trends in systems development and enterprise resource planning
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Participants Stakeholders Systems analyst Users Programmer
Individuals/organizations who are beneficiaries of the systems development effort Systems analyst Professional who specializes in analyzing and designing business systems Users Individuals who interact with the system regularly Programmer Individual responsible for modifying or developing programs to satisfy user requirements
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Technical specialists
Managers System stakeholders Programmers Systems analyst Users Technical specialists Vendors and suppliers
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Systems Analyst A programmer or consultant who designs and manages the
development of business applications. Typically, systems analysts are more involved in design issues than in day-to-day coding. However, systems analyst is a somewhat arbitrary title, so different companies define the role differently.
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Typical Reasons to Initiate a Systems Development Project
Problems with existing systems Desire to exploit new opportunities Increasing competition Perception of potential benefit by individual capable of initiating change Systems development process initiated Desire to make more effective use of information Organizational growth Merger or acquisition Change in market or external environment
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Systems development initiatives
Planning Information systems planning The translation of strategic and organizational goals into systems development initiatives Creative analysis The investigation of new approaches to existing problems Critical Analysis The unbiased and careful questioning of whether system elements are related in the most effective or efficient ways Strategic plan IS planning Systems development initiatives
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Steps in IS Planning Strategic plan
Previously unplanned system projects Developing overall objectives Identify IS projects Set priorities & select projects Analyse resource requirements Set schedules and deadlines Develop IS planning document
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Establishing Objectives for Systems Development
Performance objectives Quality or usefulness of the output The quality or usefulness of the format of the output The speed at which the output is generated Cost objectives Development costs Costs related to the uniqueness of the system application Fixed investments in hardware and related equipment On-going operating costs of the system
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Systems Development and the Internet
Applications being moved to the Internet Sales Order placement Product information access Building a static Web site Intranet tools NetDynamics SilverStream Web-Logic Novera Netscape Communications
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Systems Development Life Cycle
It’s a “cycle” Systems investigation Problems and opportunities are identified Systems analysis Existing systems and work processes are studied Systems design Defines how the information system will do what it must do to solve the problem Systems implementation System components are assembled and the new or modified system is placed into operation Systems maintenance and review Ensures the system operates and is modified to keep up with business changes
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Systems investigation (understand problem)
Systems Analysis (understand solution) Systems design (select and plan best solution) Systems implementation (place solution into effect) Systems maintenance and review (evaluate results of solution)
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Cost to make a particular change Time
Investigation Analysis Design Implementation Maintenance and review Time
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Prototyping Operational prototype Non-operational prototype
Accesses real data files, edits input data, makes necessary computations and comparisons, and produces real output Non-operational prototype A mockup or model that includes output and input specifications and formats Rapid application development (RAD) Employs tools, techniques, and methodologies designed to speed application development, automates source code generation, and facilitates user involvement in design and development activities Joint application development (JAD) Involves group meetings in which users, stakeholders, and IS professionals work together to analyze existing systems, proposed solutions, and define requirements for a new or modified system.
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Rapid Application Development
A programming system that enables programmers to quickly build working programs. In general, RAD systems provide a number of tools to help build graphical user interfaces that would normally take a large development effort. Two of the most popular RAD systems for Windows are Visual Basic and Delphi. Historically, RAD systems have tended to emphasize reducing development time, sometimes at the expense of generating efficient executable code. Nowadays, though, many RAD systems produce extremely fast code. Conversely, many traditional programming environments now come with a number of visual tools to aid development. Therefore, the line between RAD systems and other development environments has become blurred.
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Prototyping: The Iterative Life Cycle
Iteration 1 Iteration 2 Iteration 3 (final) Determine requirements Determine requirements Determine requirements Analyse alternatives Analyse alternatives Analyse alternatives Specify design Specify design Specify design Implement design Implement design Implement design User review User review Changeover
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General Model of Prototyping
Systems development initiated Investigate and analyse problem sufficiently to develop workable solution Develop prototype Put prototype into operation Refine and modify prototype Complete component or system
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End-User Systems Development Life Cycle
Any systems development project in which the primary effort is undertaken by a combination of business managers and users
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Factors Affecting Systems Development Success
Managing change Requires the ability to recognize existing or potential problems and deal with them before they become a serious threat to the success of a new or modified system Use of project management tools Schedule Milestone Deadline Critical path Program Evaluation Review Technique (PERT) Gantt chart
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Selected Project Management Software Packages
Vendor BeachBox ’98 NetSQL Partners Job Order Management Software Inc. OpenPlan Welcom Project Microsoft Project Scheduler Scitor Corp. Super Project Computer Associates
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Use of Computer-Aided Software Engineering (CASE) Tools
CASE tools automate tasks required in a system development effort and enforces adherence to the SDLC Upper CASE tools Tools that focus on activities associated with the early stages of systems development Lower CASE tools Tools that focus on the later implementation stage of systems development Integrated-CASE (I-CASE) tools Tools that provide links between upper- and lower-CASE packages, allowing lower-CASE packages to generate program code from upper-CASE package generated designs
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CASE Short for Computer Aided Software Engineering, a category of software that provides a development environment for programming teams. CASE systems offer tools to automate, manage and simplify the development process. These can include tools for: Summarizing initial requirements Developing flow diagrams Scheduling development tasks Preparing documentation Controlling software versions Developing program code Various companies offer CASE software capable of supporting some or all of these activities. While many CASE systems provide special support for object-oriented programming, the term CASE can apply to any type of software evelopment environment.
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ISO 9000 An international standard used by IS departments to ensure quality standards exist and are maintained in their products and services
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Systems Investigation
Identify potential problems and opportunities and consider them in light of the goals of the company The investigation team Managers and stakeholders IS personnel Task Undertake feasibility analysis Establish system development goals Select system development methodology Prepare system development report
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Feasibility Analysis Technical feasibility Operational feasibility
Can the hardware, software, and other system components be acquired or developed to solve the problem? Operational feasibility Can the project be put into action or operation? Schedule feasibility Can the project be completed in a reasonable amount of time? Economic feasibility Does the project make financial sense? Net present value The preferred approach for ranking competing projects and determining economic feasibility
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The Systems Investigation Report
A report that summarizes the results of the systems investigation and the process of feasibility analysis and recommends a course of action Steering committee An advisory group consisting of senior management and users from the IS department and other functional areas
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Systems Analysis Typical table of contents from a systems investigations report: Table of Contents Executive summary Review of goals and objectives System problems and opportunities Project feasibility Project costs Projects benefits Recommendations
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Sources of Data Internal Sources Users, stakeholders, managers
Organization charts Forms and documents Procedure manuals and policies Financial reports IS manuals Other measures of business processes External Sources Customers Suppliers Stockholders Government agencies Competitors Outside groups Journals, etc. Consultants
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Follow-up & clarification
Data Collection Structured Interview Unstructured Interview Direct Observation Questionnaires Statistical Sampling Identify data sources Data collection Follow-up & clarification
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Data Analysis Data analysis Data modeling Activity modeling
Manipulating collected data so that it is usable for the development team members participating in systems analysis Data modeling A commonly accepted approach to modeling organizational objects and associations that employ both text and graphics E.g, ER (entity relationship) diagrams Activity modeling A method to describe related objects, associations, and activities Data flow diagram A diagram that models objects, associations, and activities by describing how data can flow between and around them
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ER Example 1 MID Play Member Game of Golf Name Address Date paid MID
Time Score
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Data Flow Diagram Schematic description of business processes
Premise: for every activity there is some communication, transference, for flow that can be described as a data element DFDs show “logical” sequences (not physical processes)
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Process symbol Entity symbol Data-flow line Data-flow line Data store
Assign Tee time Tee time Available times Member Schedule Reservation request Group information Member tee time Course access Check member in Member Member card Member ID Date Sort scores Score card Score card Member Scores Calculate handicap Handicap Tee time
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Application Flowchart
Charts that show relationships among applications or systems Order processing application Inventory control application Invoicing application Marketing analysis application
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Grid Charts A table that shows relationships among the various aspects of a systems development effort Database applications Customer database Inventory database Supplier database Accounts receivable database Order processing applications Inventory control application Marketing analysis application Invoicing application X X X X X X X X
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Requirements Analysis
An assessment used to determine user, stakeholder, and organizational needs Strategy translation Goals and mission of the organization Systems requirements
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Screen Layout Charts May be tailored for…
Frequent users who require little descriptive information, or Infrequent users who require more descriptive information
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For frequent users… ORDER ENTRY ORDER NO. CUSTOMER SALES PERSON REGION
COMMISSION NET DOLLARS XXXXX XXX ITEM NO. QTY UNIT PRICE DOLLARS DISCOUNTS XXXXXXX XXXX XX XXXXX XXXXXX XX XX XX
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For infrequent users… Which online option would you like to perform? (Please enter an ‘X’ to make a selection) _DATA ENTRY Enter transaction and report requests for later processing _RETRIEVALS Review online information from the database: bill of materials, where-used, routing, item data
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The Systems Analysis Report
Strength and weaknesses of existing system from a stakeholder’s perspective User/stakeholder requirements for the new system Organizational requirements Description of what new information systems should do to solve the problem
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Typical Table of Contents for a Report on an Existing System
Johnson & Flores, Inc. Systems Analysis Report TABLE OF CONTENTS Background Information Problem or Need Statement Data Collection Data and Requirements Analysis Recommendations Appendixes of Documents, Tables, and Charts Glossary of Terms
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End of Chapter 12 Chapter 13
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