INFORMATION SYSTEMS AND TECHNOLOGY

INFORMATION SYSTEMS AND TECHNOLOGY
Instructor Dr. Manjunath Kamath, Associate Professor of Industrial Engineering and Management

COURSE DESCRIPTION Catalog Description
For current and potential engineering and technology managers. Knowledge of information systems and technology to lead the specification, selection, implementation, and integration of information technology in manufacturing and service organizations. Management issues involved in the use of information technology in organizations. Prerequisites Graduate standing or consent of instructor.

COURSE OBJECTIVES To develop an awareness of modern information systems concepts, such as database architectures, computing architectures, application architectures, the Internet, and Intranets, and their impact on organizational performance. To identify the different phases in the design, development, implementation, and maintenance of effective information systems. To understand the basics of content creation, management, and distribution.

COURSE OBJECTIVES To understand and evaluate commercially available systems and solutions for data management and report generation. To develop an understanding of the technical and human issues involved in managing, controlling, and administering information technologies. To explore “new” organizational structures (e.g. virtual corporations) resulting from the use of modern information systems and technology.

PRIMARY REFERENCES Alter S. (1999), Information Systems: A Management Perspective, Third Edition, Prentice-Hall, Inc., New Jersey. ( Comer, D.E. (1997), The Internet Book, Second Edition, Prentice-Hall, Inc.,NewJersey. (

TECHNICAL REFERENCES Comer D.E. (1995) Internetworking with TCP/IP Volume I: Principles, Protocols and Architectures, Third Edition, Prentice- Hall, Inc., New Jersey. Orfali R., D. Harkey and J. Edwards (1999), Client/Server Survival Guide, Third Edition, John Wiley. Yeager N.J. and R.E. McGrath (1996), Web Server Technology: The Advanced Guide for World Wide Web Information Providers, Morgan Kaufmann Publishers.

OTHER REFERENCES Gupta, U. (2000), Information Systems Success in the 21st Century, Prentice- Hall, Inc., New Jersey. Haag, S., M. Cummings and J. Dawkins (2000), Management Information Systems for the Information Age, Second Edition, Irwin McGraw-Hill, Boston. Stair, R.M. (1996), Principles of Information Systems: A Managerial Approach, Second Edition, Boyd and Fraser Publishing Company, Boston. Turban E., E. McLean and J. Wetherbe (1996), Information Technology for Management, John Wiley and Sons, Inc., New York. Whitten, J.L. and L.D. Bentley (1998), Systems Analysis and Design Methods, Fourth Edition, Irwin McGraw-Hill, Boston. (

GRADING POLICY Method of Instruction
Two seventy-five minute class periods per week. Class will consist of lecture and discussion. Grading Policy Graded work will be weighted as follows: Mid-term Examination 20% Homework (8-10 sets) 30% Term Paper 25% Final Examination 25%

GRADING POLICY Grades will be given on a 90, 80, 70, 60 basis. The instructor reserves the right to lower the curve as circumstances warrant. Homework assignments are expected to be well organized and neatly presented. They will be graded and returned to the student. Academic dishonesty will not be tolerated. When the instructor feels beyond reasonable doubt that dishonesty has occurred, he will take disciplinary action in accordance with university policies and procedures. Spring Syllabus Attachment www2.okstate.edu/acad/sylatsp00.html

TENTATIVE COURSE OUTLINE
Introduction to the Course Information System Framework and Development 1 Zachman's framework; phases in system development. Current Trends in Information System Development and Application 2 ERP; web-based systems; e-commerce; globalization. Types of Information Systems Transaction processing systems; management information systems; decision support systems; etc.

Databases and Database Management Systems 3 File systems vs. databases; database management systems; database topology; data warehouses. Computing and Communication Architectures 3 Centralized vs. distributed systems; client/server architectures; LANs; WANs; etc. Application Development Programming languages; operating systems; html; XML; etc. Internet, Intranets, and Extranets 4 Protocols - TCP/IP, http; web-servers; browsers; domain names; security technologies; etc. Information Systems Development 3 Methodologies; data, process and object models; CASE tools; prototyping.

Data Management Evaluating commercial systems; report generation; online analytical processing (OLAP); etc. New Organizational Structures Virtual/extended enterprises; supply chain systems. Organizational, Human and Ethical Issues 4 Impact on strategic planning, business processes and organizational performance; privacy and security issues; information ergonomics. Directions for New Technology

INFORMATION SYSTEMS An arrangement of people, data, processes, interfaces and geography that are integrated for the purposes of supporting and improving the day-to-day operations in a business, as well as fulfilling the problem-solving and decision-making information needs of business managers Source: Whitten, J.L. and L.D. Bentley(1998), Systems Analysis and Design Methods, pp. 38, Fourth Edition Irwin McGraw-Hill, Boston

MAIN IDEA DISCUSSED BY ZACHMAN
There is a set of architectural representations produced over the process of building a complex engineering product representing the different perspectives of the different participants.

INFORMATION SYSTEM PERSPECTIVES
L System Owners INFORMATION SYSTEM SCOPE (purpose and vision; goals and objectives; costs and benefits) System Users INFORMATION SYSTEM REQUIREMENTS (WHAT the system “is” and “must do” independent of technology) System Designer INFORMATION SYSTEM DESIGN (HOW the system will be implemented using technology) System Builders INFORMATION SYSTEM COMPONENTS (the actual, technical implementation of the system) Source: Whitten, J.L. and L.D. Bentley(1998), Systems Analysis and Design Methods, Fourth Edition Irwin McGraw-Hill, Boston

CLASSIFICATION OF STAKEHOLDERS
System owners pay for the system to be built and maintained System users are the people who actually use the system to perform or support the work to be completed System designers are the technical specialists who design the system to meet the customer requirements System builders are the technical specialists who construct, test and deliver the system into operation

MAIN IDEA DISCUSSED BY ZACHMAN
The same product can be described, for different purposes, in different ways, resulting in different types of descriptions.

DIFFERENT DESCRIPTIONS OF THE SAME PRODUCT
Material description: It talks about WHAT the thing is made of Functional Description: It talks about HOW the thing works Location Description: It talks about WHERE the flows exist

I/S ANALOGS FOR THE DIFFERENT DESCRIPTIONS

FOCUSES DATA: the raw material used to create useful information
PROCESSES: the activities that carry out the mission of the business INTERFACES: how the system interacts with people and other systems GEOGRAPHY: where the data is captured and stored; where the processes happen; where the interfaces happen

WHITTEN-BENTLEY’S ADAPTATION OF ZACHMAN’S FRAMEWORK
System Data System Processes System Interfaces System Geography Methodology S Y T E M A N L System Owners Business Subjects Business Functions System Context Operating Location Survey Phase System Users Data Requirements Business Processes Interface Requirements Communica- tion Requirements Study Phase System Designer Database Schema Application Schema Interface Schema Network Schema Configuration Phase System Builders Database Programs Application Programs Component Programs Network Programs Construction Phase

System Data System Processes System Interfaces System Geography Methodology S Y T E M A N L System Owners Business Subjects Information about the resources to be managed Business Functions Ongoing activities that support the business System Context Unit/business the new system should interface with Operating Location Not synonymous with computer center Survey Phase System Users Data Requirements How the data is or should be implemented Business Processes Discrete activities having inputs, outputs and start/end times Interface Requirements How users interact with the system Communica- tion Requirements Technology independent information resource requirements Study Phase

System Data System Processes System Interfaces System Geography Methodology S Y T E M A N L System Designer Database Schema Translation of data requirements into databases Application Schema Implementa- tion of bus.processes using computers Interface Schema Properties, system states, events and their responses Network Schema Model indentifying all centers involved in an application Configuration Phase System Builders Database Programs Closest to database technology foundation Application Programs Language based representation of what a process should do Component Programs GUIs - Visual BASIC Delphi Powerbuilder Network Programs Machine readable specifications of computer communication parameters Construction Phase

INTERESTING FEATURES OF THE FRAMEWORK
Each element on either axis of the matrix is explicitly differentiable from all other elements on that one axis. These representations are not merely successive levels of increasing detail but are actually different representations. Source: Whitten, J.L. and L.D. Bentley(1998), Systems Analysis and Design Methods, Fourth Edition Irwin McGraw-Hill, Boston

SYSTEM DEVELOPMENT PHASES
Source: Whitten, J.L. and L.D. Bentley(1998), Systems Analysis and Design Methods, Fourth Edition Irwin McGraw-Hill, Boston

Enterprise Resource Planning (ERP) System
An ERP system is a commercial software package that enables a company to integrate the data used throughout the entire organization. May be the most important development in the corporate use of information technology in the 90s. (Source: Davenport, 1998)

Information Fragmentation
Information is typically spread across numerous separate computer systems, each housed in individual function, business unit, region, factory or office. This results in redundant data, need for reentering or reformatting data, etc. Interoperability problems exist between individual systems. (Source: Davenport, 1998)

Information Integration
At the core of an ERP software system is a single comprehensive database, which streamlines the flow of information throughout a business. The database collects data from and feeds data into modular applications supporting virtually all of a company’s business activities. (Source: Davenport, 1998)

ERP Software Modules Financials Human Resources and Pay Roll
Distribution/Logistics Sales & Marketing Manufacturing Product Data Management Material Planning Resource & Capacity Planning Shop Floor Management Quality Management, etc. (Source: Davenport, 1998)

AN ERP SYSTEM Managers and Stakeholders Sales & Reporting Delivery
Financial S U P L I E R C u s t o m e r Central database Manufac -turing Sales Force & Customer Service Rep Back- Office Ad and Workers Service Human Resource Mgmt Inventory and Supply Employees (Source: Davenport, 1998)

Big Five - JBOPS OneWorld (www.jdedwards.com) BaanERP (www.baan.com)
Oracle ( PeopleSoft ( SAP’s R/3 (

ERP Implementation ERP systems
require a major commitment and investment, often require companies to modify some of their processes to accommodate the software, and can take a long time to implement. (Source: Davenport, 1998)

ERP & Business Processes
A company often has to modify some of its business processes to accommodate the ERP software system. The organizational changes resulting from these modifications could easily overwhelm a company. Furthermore, some of these modifications may not be acceptable to the company. (Source: Davenport, 1998)

Benefits of ERP Systems
Automated update of related information when new information is entered in one module. Direct access to a wealth of real-time operating information. These benefits could translate into dramatic gains in productivity and speed. (Source: Davenport, 1998)

Current Trends in ERP Software
Easy-to-install and relatively inexpensive ERP modules. Enterprise extension software that plugs “holes” within the factory expands ERP-style benefits beyond the factory. (Source: Bylinsky, 1999)

ERP Modules vs ERP Systems
ERP modules designed specifically for manufacturers using newer concepts. For example, Pivot.Man from Pivotpoint. In many cases they don’t force a company to change its operations to suit the software. (Source: Bylinsky, 1999)

Enterprise Extension Software
These hook on to traditional ERP systems as well as to the newer ERP modules. Within the factory, Manufacturing Execution Systems (MES) bridge the gap between the plant and ERP programs. For example, Dynamic Performance Monitoring (DPM) software from Foxboro. (Source: Bylinsky, 1999)

Enterprise Extension Software (continued)
Front-office and back-office software that extends ERP-style benefits beyond the factory. An example of a back-office software is CSM (Component and Supplier Management) software from Aspect Development Corporation, for the in-bound supply chain. (Source: Bylinsky, 1999)

Enterprise Extension Software (continued)
On the front-office side, customer relationship management (CRM) is the hottest area. Siebel systems is a leading manufacturer of CRM software. The Big Five are also developing CRM extensions for their ERP systems. (Source: Bylinsky, 1999)

e-Commerce Using the Web and other electronic means for buying, selling and distributing goods and services (Source: Alter, 1999)

Electronic Data Interchange (EDI)
Allows companies to exchange documents in a structured and computer-processable format. Helps to automate and streamline a business by eliminating or simplifying clerical tasks, speeding information transfer, reducing data errors, and eliminating business processes. (Source: Fu et al., 1999)

e-Commerce Evolution from VAN-based EDI to Web-based EDI.
Web-based EDI addresses the needs of small and medium-sized firms. Business-to-consumer and business-to-business. (Source: Fu et al., 1999)

Evolution of e-Commerce
VAN-based EDI needs considerable infrastructure application, translation software and communication network over private VANs Web-based EDI low-cost transport mechanism world-wide connections XML documents (Source: Fu et al., 1999)

Transaction Processing System (TPS)
A transaction is a business event that generates or modifies data stored in an information system. A TPS collects and stores data about transactions and sometimes controls decisions made as part of a transaction. A TPS focuses on record keeping and control of repetitive clerical processes. (Source: Alter, 1999)

TPS (Contd.) Design of a TPS is based on TPSs are capable of
execution details of the transactions; data content and format; and rules and policies to be enforced. TPSs are capable of enforcing rules and work procedures; detecting errors, such as missing data, invalid data, and inconsistent data; and automating certain decision-making functions. (Source: Alter, 1999)

TPS (Contd.) Batch Processing: Information on individual transactions is collected and stored. Based on a schedule or number accumulated the transactions are processed later to update the database. Examples are processing of checks and other paper forms, generation of paychecks, and weekend deposits into ATMs. Problems - error correction & data currency. (Source: Alter, 1999)

TPS (Contd.) Real-time Processing: Each transaction is processed immediately. An advantage is immediate error correction. Examples are airline reservation systems and bursar/bank systems. Characterized by quick response and high availability. (Source: Alter, 1999)

ERP System - a TPS? An ERP system encompasses transaction processing done in various functional areas of an enterprise. Actually an ERP system is a hybrid system that has characteristics of many of the individual information system types including the TPS. (Source: Alter, 1999)

Management Information System (MIS)
MISs generate summary information for monitoring performance, maintaining coordination, and providing background about the organization’s operation. Users are both managers and the employees who receive feedback about performance indicators. MISs extract and summarize data from TPSs. (Source: Alter, 1999)

MIS (Contd.) Typically provide pre-specified reports on a scheduled basis. MIS provides information; people decide how to improve performance. Executive Information Systems (EISs) take MISs to the next level. (Source: Alter, 1999)

Executive Information System (EIS)
EISs offer a highly interactive system that provides managers and executives flexible access to information for monitoring operating results and general business conditions. Executives can “drill down” to understand specific items of concern in more detail. Data is replenished periodically from internal and external sources. (Source: Alter, 1999)

EIS (Contd.) Typical characteristics of EISs are
user-friendly interfaces; variety of formats (tables, graphs, etc.); triggers for exceptional conditions; multiple levels of detail;and customizable reports. EISs help executives find the information they need whenever they need it and in whatever form is most useful. (Source: Alter, 1999)

Decision Support System (DSS)
A DSS is an interactive IS that provides information, models, and data manipulation tools to help make decisions in semi-structured and unstructured situations. In contrast to MIS, a DSS supports managers and professionals doing largely analytical work in less structured situations. (Source: Alter, 1999)

DSS (Contd.) The traditional DSS approach includes interactive problem solving; direct use of models; user-controllable methods for displaying and analyzing data; and formulating and evaluating alternatives. Examples range from spreadsheets to customized simulation or optimization models focusing on specific situations. (Source: Alter, 1999)

DSS (Contd.) DSSs support repetitive decision making by structuring the decision to some extent and defining procedures and formats. An example of the repetitive case is the use of a DSS by insurance agents to help customers choose the “right” insurance policy - options, cost and benefits. (Source: Alter, 1999)

DSS (Contd.) DSSs support non-repetitive decision making by providing data, models, analytical tools, and interface methods. An example is a system that helps marketing managers evaluate alternative marketing plans and track results. Data includes internal sales results and external market research databases. (Source: Alter, 1999)

New Approaches to DSS Online Analytical Processing (OLAP) and data mining. OLAP is the use of online data analysis tools to explore large transaction databases. Data mining is the use of data analysis tools to find patterns in large transaction databases. (Source: Alter, 1999)

Data Mining (Contd.) Examples are customer buying patterns in grocery stores and statistical profiles of customers who are likely to switch long-distance carriers. One of the difficulties in data mining is the problem of differentiating between meaningful and spurious patterns. (Source: Alter, 1999)

Execution Systems These systems directly support people doing the value-added work in an organization. Examples are systems that help plastic surgeons design operations and show likely results to their patients. Expert or knowledge-based systems are one type of execution systems. (Source: Alter, 1999)

Expert Systems Expert systems support the intellectual work of professionals engaged in design, diagnosis, or evaluation of complex situations requiring expert knowledge in a well-defined area. Common applications are medical diagnosis, troubleshooting, chemical analysis, data interpretation, etc. (Source: Alter, 1999)

Office Automation Systems
An OAS facilitates everyday information processing tasks in offices and business organizations. They include a wide array of productivity tools. Spreadsheets Word processors, desktop publishing tools Presentation packages Personal database systems (Source: Alter, 1999)

Communication Systems
The broad categories of communication systems are Teleconferencing Messaging systems - , v-mail, and fax Groupware (e.g. Lotus Notes) Intranets and extranets Knowledge management systems (Source: Alter, 1999)

Database A database is a logically coherent collection of data with some inherent meaning e.g. address book A database is designed, built, and populated with data for a specific purpose

Database A database may be generated and maintained manually, for example, a library card catalog. A computerized database is usually maintained by a set of programs.

Data Hierarchy File (Collection of related records)
Record (data elements that relate to a particular object or activity) Data element (smallest unit of data)

Traditional Approach Programming with files or file-processing
Files linked to a specific application Structure of data files is embedded in the application programs

File Processing - Disadvantages
File structure changes usually result in program changes Data redundancy or duplication Wasted space Naming problems Inconsistency because of lack of synchronization in updating the duplicated data

File Processing -Disadvantages
Diffused data ownership programmers “own” data accessed by their programs Result - inconsistent, inaccurate, and unreliable information

Database Approach A single repository of data which is accessed by various users Database system contains the database and a complete description of the database called meta-data

Database Approach - Advantages
Program - data independence Ability to change data structure without making changes to the programs User is not constrained by the physical organization of data

Database Management System (DBMS)
DBMS is a collection of programs that enables users to create and maintain a database DBMS is a general-purpose software that facilitates the process of defining constructing and manipulating databases for various applications

DBMS (Contd.) DBMS functions
Defining a database (data types, structures, and constraints) Constructing the database (storing the data) Manipulating the database (querying, updating and report generation) DBMS software + database = database system

A Simplified Database System Environment
Users/Programmers DATABASE SYSTEM Application Programs/Queries DBMS Software Software to Process Queries/Programs Software to Access Stored Data Stored Database Definition (Meta-Data) Stored Database

DBMS (Contd.) Data hierarchy in a Database Approach
Database (collection of interrelated files) File Record Data element Means to integrate the contents of files that have logical relationship

Database Structures Logical integration of files through explicit relationships - for example, “link” fields in a hierarchical structure Implicit relationships - relationships that can be implied from existing record data as in a relational structure

Database Approach - “Disadvantages”
Need for DBMS software which could be expensive Larger hardware configuration may be needed Dedicated staff

Database Staff Database Administrator (DBA)
authorizes access to the database co-ordinates and monitors database use acquires software and hardware resources accountable for security and response time problems

Database Staff (Contd.)
Analysts/Database designers get user requirements identify data to be stored choose appropriate structures develop a “view” of the database that meets user requirements Programmers

Computing Architectures
Centralized Computing Multiple users access a central computer (mainframe/midrange) via remote terminals. Central computer performs all the computations and controls all the peripherals. a.k.a. “host-centric” computing. Greater security is the key advantage. Total reliance on the central computer is the key disadvantage.

Centralized Computing (Contd.) Other issues are managing on-line user requests and peak-load problems. Centralized functions still needed for large business operations; on-line access to databases for airlines, distributions, & large manufacturers.

Personal Computing Individual microcomputers with user friendly GUI interfaces. Greater flexibility for individual users is the key advantage. Difficulty in sharing the work individuals do and the duplication of underutilized hardware and software and the key disadvantages.

Distributed Computing
Multiple workstations are linked using a network to share data and computing resources. Advantages are sharing of data, messages and work and sharing of resources. Complex to administer; security and control issues -- access privileges for shared items.

Network Computing Combines benefits of centralized computing with the flexibility and responsiveness of distributed computing. Multiple network computers (NCs) are linked to a central server, which provides links to other servers. NCs do not contain hard disks.

Network Computing (Contd.) Greater sharing of work and resources and easier to administer than distributed computing. Advantages are cheaper network computers, centralization of data and programs and greater data security. Disadvantages are reliance on centralized control and the relative immaturity of software designed to support this architecture.

Client/Server Computing
Client + Server = Distributed Computing (Comer 1994). Client/Server computing forms the basis for distributed computing. Facts - Programs communicate and not computers. Computers can run multiple programs at one time. A server program offers a service. A client program is a consumer of services.

Distinguishing Characteristics of Client/Server Computing (Orfali et al. 1999) Service - Server is a provider & client is a consumer of services. Shared resources - A server can service many clients simultaneously and regulate their access to shard resources.

Distinguishing Characteristics of Client/Server Computing Transparency of location - The server is a process or program that can reside on the same machine as the client or on a different machine across the network. A program can be a client, a server, or both. Mix-and match - The ideal client/server software is independent of hardware or OS platforms.

Distinguishing Characteristics of Client/Server Computing Message-based exchanges - clients and servers interact through a message-passing mechanism. Encapsulation of services: Message specifies “what “ and not “how”.

Distinguishing Characteristics of Client/Server Computing Scalability: Horizontal - add/remove clients; Vertical - larger and faster server or load distribution across multiple servers; Integrity - Server code and server data are centrally managed

Types of Servers The idea of splitting an application along client/server lines results in various forms of networked software solutions. Each of these solutions is distinguished by the nature of service provided. File servers, Database servers, Transaction servers, GroupWare servers, etc.

File Servers Client (usually a PC) requests for a file of records over a network. Many message exchanges over the network to find the requested data. File servers are key to shared repositories of documents, images, engineering drawings, and other large data objects.

Database Servers Client passes SQL requests as messages to the database server. DBMS code and data reside on the server. Application code resides on the client. Server performs the search and returns the results to the client. Play a key role in data warehousing and decision support systems.

Transaction Servers Client invokes remote procedures or services on the server. Remote procedures execute a group of SQL statements called transactions. Application is called Online Transaction Processing or OLTP.

Transaction Servers Client side usually includes a GUI; server side SQL transactions. Quick response, high security and integrity characterize OLTP application.

GroupWare Servers Management of semi-structured information such as text image, mail, bulletin boards, and the flow of work. Lotus Notes & MS Exchange are examples. Communication middleware between the client and the server is vendor-specific. is becoming a standard messaging middleware.

Fat Clients and Fat Servers
How is the application split between the client and the server? GUI Data Application Client Server Fat Server Fat Client Source: Orfali et al. 1999

More traditional form of client/server. Bulk of the application runs on the client. Eg. File server model.

Most of the code runs on the server; mission-critical applications. Network interchanges are minimized. Eg. Transaction Server model; server encapsulates the database; client issues procedure calls (invokes services).

2-Tier, 3-Tier, N-Tier Same basic idea as fat servers and fat clients.
How are the functional units of a client/server application assigned either to the client or to one or more servers? Typical functional units - User Interface, Business Logic, and the Shared Database. Middleware is used to communicate between the tiers.

2-Tier, 3-Tier, N-Tier In a 2-Tier system, the business or application logic is on the client with the GUI or on the server with the database or both. E.g., File and Database servers. In a 3-Tier system, the application logic lives in the middle tier. E.g., Web Application server.

2-Tier Client/Server Architecture
GUI and Application SQL, File I/O HTTP, etc. Database DBMS/Legacy Tier 1 - Client Middleware Tier 2 - Server

3-Tier Client/Server Architecture
GUI/ Browser HTTP, etc. SQL, Database DBMS/Legacy Application Logic Tier 1-Client Middleware Tier 2- Server Tier 3-Database

Middleware A vague term that covers all the distributed software needed to support interactions between clients and servers. (Orfali et al. 1999) Performs whatever translation is necessary to make a client’s request understandable to a server program. (Alter 1999)

Middleware Starts on the client side that invokes a service, covers the transmission of the request over the network and the resulting response. Middleware does not include either the software that provides the actual service or the database. On the client side, it does not include the interface.

Middleware (Contd.) It does include software used to co-ordinate inter-server interactions. Represents a rapidly changing and growing area. (From $ 1.7 billion in 1997 to $ 7 billion in 2002 according to IDC.)

2-Tier Client/Server Simplicity is the biggest selling point.
Well suited for departmental applications (DSS, small-scale GroupWare) or simple Web publishing applications. Scalability problems - hard to deploy and manage fat clients on a large scale. Difficulty in managing software on remote desktops.

3-Tier (N-Tier) Client/Server
For large-scale, enterprise-wide applications that serve thousands of enterprise clients. Applications are split into hundreds of components and distributed across multiple servers.

In theory, 3-Tier systems are scalable - load distribution across multiple servers. flexible - all 3 tiers on different computers; second and third on the same computer; second tier across multiple servers; etc. More secure - data tables are encapsulated.

In theory, 3-Tier systems are Easier to administer - less logic on the client to manage. More responsive - only service requests and responses (and not raw data) are sent between the client and the server.

3-Tier Vs. N-Tier Middle tier in most 3-Tier applications is often implemented as a collection of components. Components are used in a variety of client-initiated business transactions. Components co-operate while responding to a client request. Components can encapsulate legacy applications running on main frames.

Component-based Architecture
Advantages of component-based applications in the “middle” tier. Lend themselves well to a small-team, incremental development approach. Components can be reused. Components encapsulate details of application logic.

Component-based Architecture
Advantages of component-based applications in the “middle” tier. Clients can access data and functions easily and safely. Possibility of buying ready-made components. Basis for suites of applications.

Lecture 6 Computing Architectures
References: Alter S. (1999), Information Systems: A Management Perspective, Third Edition, Prentice-Hall, Inc., New Jersey. Chapter 8 pp Comer, D.E. (1997), The Internet Book, Second Edition, Prentice-Hall, Inc., New Jersey. Chapter 15 pp Orfali R., D. Harkey and J. Edwards (1999), Client/Server Survival Guide, Third Edition, John Wiley. Chapters 1-3

Client/Server Architectural Styles
2-Tier 3/N-Tier Fat Client Fat Server Adapted from Rob & Coronel (1997)

Middleware Middleware software provides the means through which clients and servers communicate to perform specific actions. Operates at 2 levels: Physical level deals with communications between client and server computers. Logical level deals with communications between client and server processes.

Types of Networks Three types of networks transmit data between computerized devices: local area networks (LAN) wide area networks (WAN) value added networks (VAN)

LANs A computer communication technology is classified as a LAN if it provides a way to interconnect multiple computers and devices across short distances - e.g. floor of a building. Computers and devices need additional hardware to connect to a LAN. A LAN is independent from the computers it connects.

LANs LANs support distributed computing in small organizations and in departments of larger organizations and offer the following benefits. Sharing equipment sharing personal files sharing databases administering software link to other networks

Network Topology A network topology is the pattern of connections between the devices on a network (LAN or other types). Three main network topologies bus topology ring topology star topology

Bus Topology Each node (computer, device) is attached to a common cable called bus. A device can access any other device directly by using its address. Message broadcast to all nodes at the same time and only the recipient device responds by accepting it.

Bus Topology Addition/removal of a node does not affect other nodes.
Network performance degrades as traffic increases. Ethernet uses a bus topology.

Ring Topology Computers and devices are connected directly in a continuous loop. Messages must be re transmitted by all the nodes between the source and the destination. IBM’s token ring network. Nodes can be added or removed; requires special effort while network is running.

Star Topology All messages go through a central node - computer or hub. All network messages travel through the central node. Nodes can be added or removed without affecting the operation of the rest of the network.

Star Topology Expansion is limited by processing power of central node. Reliability problems; network goes down when the central node is down.

Networking Cabling Most LANs use either twisted-pair wire or coaxial cable. Fiber optic cable is used rarely for LANs. But it offers the highest data transmission quality and allows greater distances between cables. Wireless communications media, such as radio and satellite, are an alternative to cables.

Data Transmission Baseband transmission Broadband transmission
Most LANs use this. Entire capacity of the cable is used to transmit a single digitally coded signal. Ethernet using coaxial cable (at 10 or 100 Mbps) is a common baseband network. Broadband transmission capacity of the cable is divided into separate frequencies to transmit voice, data, and video signals simultaneously.

Connecting Networks Links between LANs and between LANs and other networks is accomplished using bridges, routers, repeaters, and gateways. A bridge is a device that connects two LAN segments, which may be similar or dissimilar.

Connecting Networks (Contd.)
A router is a device that forwards data packets from one LAN or WAN to another. It is at a higher level than a bridge and is sensitive to protocols. Routers are the backbone of the Internet. A repeater is a device that is used in LANs to regenerate signals to span longer distances.

Connecting Networks (Contd.)
A gateway is a computer that performs protocol conversion between dissimilar networks. Sometimes a “go-between” two or more networks that use same protocols.

Wide Area Networks (WANs)
A communications network that covers a wide geographic area, such as a state or a country. Communications backbone for a large distributed organization.

WANs (Contd.) Often implemented in the form of a virtual private network (VPN), a private network configured within a public network. Customers physically share backbone trunks with other customers. Trend is VPN over the Internet. WAN can link to workstations or terminals through LANs.

Value Added Networks (VANs)
VANs are public data networks that “add value” by transmitting data and providing access to commercial databases and software. Customers subscribe to VANs and also pay additional fees based on usage.

Value Added Networks (VANs)
Used in EDI, where forms are collected in an electronic mailbox, translated and forwarded to recipients with guaranteed delivery. Internet is becoming an alternative to VANs for many applications that do not involve huge amounts of data.

OSI Reference Model Open Systems Interconnection reference model
Seven-layer network architecture model of data communication protocols developed by ISO and CCITT. Each layer specifies particular network functions.

OSI Reference Model Layer 7, the application layer, the highest layer of the model, defines the way applications (client or server) interact with the network. Layer 6, the presentation layer, includes protocols that are part of the operating system, and defines how information is formatted for display or printing and how data is encrypted, and translation of other character sets.

OSI Reference Model Layer 5, the session layer, coordinates communication between systems, maintaining sessions for as long as needed and performing security, logging, and administrative functions. Layer 4, the transport layer, controls the movement of data between systems, defines protocols for structuring messages, and supervises the validity of transmissions by performing error checking.

OSI Reference Model Layer 3, the network layer, defines protocols for routing data by opening and maintaining a path on the network between systems to ensure that data arrives at the correct destination node. Layer 2, the data-link layer, defines the rules for sending and receiving information from one node to another between systems.

OSI Reference Model Layer 1, the physical layer, governs hardware connections and byte-stream encoding for transmission. It is the only layer that involves a physical transfer of information between network nodes.

Packet Switching Packet is a unit of data that can be transferred at one time. Packet includes a header and the data. Packets are of variable sizes with a maximum size limit. All data is transferred across the Internet in packets.

Packet Switching (contd.)
Packet switching is the process of routing communications traffic in the form of data packets from a sender to the (correct) receiver. LANs and WANs use packet switching. Packet switching avoids delays; short messages need not wait for long transfers to complete.

Packet switching permits multiple pairs of computers to communicate simultaneously in a shared network. Computers take turns sending packets. Interface hardware handles sharing automatically.

Each device connected to a network contains a small computer that handles the communication. Network software on the sender side divides data into packets. Network software on the receiver side reassembles the packets.

Internet - A Network of Networks
Interconnection of multiple packet switched networks. Multiple packet switching technologies - different speed, distances, & cost characteristics Internet provides a mechanism to interconnect arbitrary networks software to transfer data across the connections

Routers Computers with special purpose software that interconnects networks. Forward packets from one computer to another. Routing is the process of selecting a network over which to send a packet. Router can interconnect diverse technologies, for example, a LAN to a WAN.

Backbone Network & Sites
A major WAN to which other networks attach is called a backbone network. Example: vBNS - very high-speed Backbone Network System (by MCI in 1995). Sites reached by the backbone are called backbone sites. At each backbone site, a router connects a LAN to the backbone.

Wide Area Backbone Wide Area Backbone Router net at 6 net at 7
LAN at site 1 LAN at site 2 LAN at site 3 LAN at site 4 LAN at site 5 LAN at site 6 LAN at site 7 Router net at 6 net at 7 net at 2 net at 3 Source: Comer, D.E. (1994), The Internet Book, Second Edition, Prentice-Hall, Inc., New Jersey.

IP - Internet Protocol A Communication Protocol is an agreement that specifies a common language two computers use to exchange messages. A protocol specifies exact format & meaning of each message conditions under which a message can be sent how a computer should respond to a message

IP - Internet Protocol (contd.)
IP specifies how a packet must be formed, and how a router must forward it to its destination. IP software is needed on a computer connected to the Internet. IP software is memory resident. Internet packets are called IP datagrams.

IP - Internet Protocol (contd.)
IP transforms a collection of networks and routers into a seamless communication system. IP makes the complex internal physical structure of the Internet transparent to the end user.

Router connecting networks a and b
Internal Structure f e d c b a Source: Comer, D.E. (1994), The Internet Book, Second Edition, Prentice-Hall, Inc., New Jersey. Network a Router connecting networks a and b Computer attached to network d

IP Datagrams & Network Packets
IP datagram defines a standard format for all Internet packets. IP datagram travels inside a network packet. IP datagram is data within a network. Router creates a new network packet for transmission across another network. Datagram is processed by software on the destination computer.

Internet or IP Address IP address is a unique number assigned to a computer. Computer stores an IP address in 4 bytes. IP address is displayed as 4 decimal numbers separated by periods, IP addresses are not random; prefix is the same for all computers on the same network.

Routing Example e a f b c C3 C2 C1 d Computer C2 Router 1 Computer C3
Source: Comer, D.E. (1994), The Internet Book, Second Edition, Prentice-Hall, Inc., New Jersey.

TCP - Transmission Control Protocol
In addition to IP software, most of the computers that connect to the Internet also run TCP software. TCP/IP - an entire set of Internet communication protocols. TCP enables two computer programs to communicate across the Internet - connect, exchange data, and disconnect.

TCP (contd.) TCP makes the Internet reliable.
Checks for lost datagrams that were discarded by routers. Puts incoming datagrams in the order they were sent. Checks for duplicate datagrams. TCP handles the problem of lost datagrams by using timers and acknowledgements.

TCP (contd.) TCP software on the receiver side sends an acknowledgement back to the sender. TCP on the sender side starts a timer when it sends data. If an ack. arrives before the timer expires then the TCP cancels the timer, else it retransmits another copy. TCP’s timer mechanism adapts to “distance” of destination and Internet traffic delays.

Names for Computers Users prefer alphabetic names to IP addresses.
Each computer on the Internet must have a unique name. Names with many parts Full Name = local name + organization suffix E.g. = www + okstate.edu Full Name = computer name + dept. name + organization suffix E.g. cimctr.inden.okstate.edu

Names for Computers (contd.)
Domain Name System (DNS) is a software that translates a domain name to an IP address. DNS uses the client/server approach; application program contacts the domain name server to get the IP address. Domain name servers store names of computers at only one company or enterprise.

Names for Computers (contd.)
Computer name lookup is automatic. Application asks a local domain name server and if needed this server then contacts a remote domain name server. There is no correspondence between the parts of a domain name and the parts of its IP address.

Reasons for Internet’s success
IP provides flexibility Accommodates many types of hardware - WAN or LAN, high-speed or slow, wired or wireless, etc. TCP/IP standards specify how to send IP datagrams on each type of network. TCP provides reliability Automatically adapts to Internet conditions Makes reliable communication possible even during periods of congestion.

Network/Information Security
“The terms network security and information security refer in a broad sense to confidence that information and services available on a network cannot be accessed by unauthorized users.” (Comer 1995) Need to protect Physical resources (disks, computers, cables, bridges, routers, etc.) Abstract resources (information)

Security Requirements
Data integrity - protecting information from unauthorized change. Data availability - guaranteeing that outsiders cannot prevent legitimate data access. Confidentiality/Privacy - preventing unauthorized listening.

Security Requirements (contd..)
Authentication - ensuring that a message indeed originated from its apparent source. Non-repudiation - ensuring that a party to a transaction cannot subsequently deny that this transaction took place.

Internet Security Mechanisms
Authentication Mechanisms: IP source authentication, Public key encryption Privacy Mechanism: Encryption Access Control Mechanisms: Internet firewall Authentication and privacy mechanisms can be added to application programs. Access control requires basic changes to Internet infrastructure.

IP Source Authentication
Server maintains a list of valid IP source addresses. Weak because it can be broken easily. An imposter can gain control of an intermediate router and impersonate an authorized client. An imposter can also impersonate a server.

Public Key Encryption System
Each end-entity has a cryptographic key pair a private key that is kept secret at that end-entity, and a public key which is distributed. Keys, which are large integers, are used to encode and decode messages. A message encoded using one key can be decoded using the other.

Public Key Encryption System (contd.)
Message encrypted by a public key can only be decrypted by the holder of the corresponding private key. Private key can be used to generate a digital signature and anyone knowing the public key can authenticate it. Guessing or calculating the secret private key is an extremely difficult task.

Public Key Encryption System (contd.)
Public key encryption scheme can also handle the problem of privacy. Sender uses the receiver’s public key to encode the message. Receiver uses it’s private key to decode the message. Messages can be encoded twice to authenticate the sender and to enforce privacy. First with the sender’s private key and then with the receiver’s public key.

Certificates and Certification Authorities
To ensure authenticity, public keys are generally distributed in the form of certificates. A certificate contains a public key value identity of the holder of the corresponding private key digital signature of the certification authority (CA)

Certificates and Certification Authorities (contd.)
A CA is a trusted party whose public key is known, e.g., VeriSign, Inc. The recipient uses the public key of the CA, to decrypt the sender's public key in the certificate. The most vulnerable part of this method is the CA’s private key, which is used to digitally sign the certificate.

Messages exchanged in a typical SSL handshake
ClientKeyExchange A random challenge, encrypted with the server’s public key Certificate Server sends its certificate ServerHello Server selects a cipher suite, usually RSA ClientHello A list of cipher suites supported CLIENT SERVER HTTP communication begins over the secure channel Messages exchanged in a typical SSL handshake Source: Abbott, S The Debate for Secure E-Commerce. Performance Computing, February 1999, p.p

Secure Sockets Layer (SSL)
The leading security protocol on the internet. Developed by Netscape. At the start of an SSL session, the browser sends its public key to the server. Server uses the browser’s public key to encrypt a secret key and sends it to the browser. During the session, the server and browser exchange data via secret key encryption.

SSL (contd.) SSL has merged with other protocols and authentication methods to create a new protocol known as Transport Layer Security (TLS). Typically only server authentication is done. Authentication of browser’s (user’s) identity requires certificates to be issued to users.

Internet Firewalls Firewall protects an organization’s internal networks, routers, computers, and data against unauthorized access. Security perimeter involves installing a firewall at each external connection. For effective control all firewalls must use exactly the same access restrictions.

Internet Firewall Implementation
A firewall must handle datagrams at the same speed as the connection to the outside world. To operate at network speeds, routers include a high-speed filtering mechanism. Filters form the basic building blocks of a firewall.

Packet Filters Provides a basic level of network security at the IP level. Filtering is based on any combination of source IP address, destination IP address, protocol, source protocol port number, and destination protocol port number. Packet filters do not maintain context or understand the application they are dealing with.

Packet Filters Specifying the datagrams that should be filtered is not very effective. Instead we specify which datagrams to admit. Security concerns IP spoofing (mimicing IP addresses of trusted machines) IP tunneling (one datagram is temporarily encapsulated in another)

Packet Filters “If an organization’s firewall restricts incoming datagrams except for ports that correspond to services the organization makes available externally, an arbitrary application inside the organization cannot become a client of a server outside the organization.” (Comer, 1995)

Proxy Firewalls Most secure form of firewall
All incoming traffic is tunneled to the appropriate proxy gateway for mail, HTTP, FTP, etc. Proxies then direct the information to the internal network. Proxies are applications that make decisions based on context, authorization, & authentication rules instead of IP addresses.

Proxy Firewalls (contd.)
Proxy firewall operates at the highest level of the protocol stack. Proxies are relays between the Internet and the organization’s private network. Proxy’s firewall address is the only one available to the outside world. Some firewalls combine router and proxy techniques to provide more security.

Topics Covered Types of software. Changing nature of programming.
Object Oriented Programming. Four generations of programming languages. Operating systems. Source: Alter 1999

Types of Software Application Software End-User Software
System Development Software System Software Source: Alter 1999

Application Software Purpose Examples
Tells the computer how to perform tasks that structure or automate specific steps in business process that apply only in specific settings. Examples Billing System, Inventory System Source: Alter 1999

Application Software Effect on end user Generality
Automates or structures steps in business processes. Generality Used for a specific type of business process in a specific business or group of similar business. Source: Alter 1999

End-User Software Purpose Examples
Tells the computer how to perform tasks that support general business processes that apply in many settings, such as writing memos or performing calculations. Examples Word processor, spread-sheet software, drawing package, etc. Source: Alter 1999

End-User Software Effect on end user Generality
Hands-on tools for the end user; may be used to develop small systems. Generality Concerned with a general business processes that could apply in many firms. Source: Alter 1999

System Development Software
Purpose Helps analysts and programmers build information systems. Examples Compiler, DBMS, CASE system. Source: Alter 1999

System Development Software
Effect on end user No direct effect on end user; helps technical staff produce better information systems. Generality Used to build a general class of systems, such as business applications. Source: Alter 1999

System Software Purpose Examples
Controls or supports the operation of the computer system so it can execute application software or end-user software. Examples Operating system, utility program, etc. Source: Alter 1999

System Software Effect on end user Generality
Controls computer system operations so that the end user can use it. Generality Concerned with how a computer operates, regardless of what business problem it is solving. Source: Alter 1999

The Changing Nature of Programming
User Requirements Executable Machine Code ??? Automatic Automatic Human ??? Object Oriented Programming(???) Automatic Human Fourth Generation Language Human Automatic Higher Level Language Automatic Human Automatic Human Assembly Language Human Machine Language Source: Alter 1999

Trends in Software Development
Greater Nonprocedurality the focus is more on what should be accomplished and not how it should be accomplished by the computer. programming is more directly linked to analysis, which uses logical models. greater focus on the business problem, instead of computer-related details. Source: Alter 1999

Greater Modularity and Reusability programs are designed as a set of self-contained modules that work together. modularity makes designing and testing easier. example is separating user interfaces and application logic. reusability is achieved through the use of pre-existing modules. Source: Alter 1999

Greater Machine and Data Independence Java for Internet applications. client-server applications. Tighter Links between Analysis and Programming automatic translation from requirement models to programs using CASE systems. Source: Alter 1999

Object Oriented System
An OO system is a collection of interacting objects that communicate through message passing in order to accomplish a goal/task. An object consists of data (attributes) and operations (methods) that act on the data. A message from Object A to Object B corresponds to invocation of a method/member function in Object B. Source: Ramamoorthy and Chillakanti 1991

Object Oriented System
Objects are categorized into “classes”. A class defines a template from which objects are created. The template contains a general description that is shared by one or more objects. The description includes the data and the operations associated with objects of that class. Source: Ramamoorthy and Chillakanti 1991

Object Oriented Programming
Starts with identification of objects and classes. Each class of objects has actions associated with it. These actions have methods for performing the action. All members of a class inherit methods of classes preceding it in the hierarchy. Source: Alter 1999

Classes and Objects CLASS Document Spreadsheet SUBCLASS Memo model
Spreadsheet model for calculating discount Memo to John Doe, 5/7/98 Memo to Jane Doe, 8/11/98 Source: Alter 1999

Inheritance and Methods
Document CLASS Methods for * opening * closing * saving * printing Spreadsheet model Memo SUBCLASS Memo to John Doe, 5/7/98 Memo to Jane Doe, 8/11/98 OBJECT Spreadsheet model for calculating discount Source: Alter 1999

Message Passing A User Memo to Jane Doe, 8/11/99 print
Source: Alter 1999

Polymorphism print Memo to Jane Doe, 8/11/99 A User Spreadsheet model
for calculating discounts print Source: Alter 1999

Object Oriented Development
identification of classes determining the attributes and methods associated with each class determining the various kinds of relationships among classes inheritance - class-subclass composition - class-component business - class-class

Four Generations of Programming Languages
Machine Languages Assembly Languages Higher Level Languages Fourth Generation Languages Source: Alter 1999

Higher-Level Languages
Known as 3GLs. A program called compiler translates 3GL programs (source code) to machine language programs (object code). An interpreter of a 3GL translates and executes each successive line of a program. Source: Alter 1999

Fourth Generation Languages
4GLs are a loosely defined group of programming languages that make programming less procedural than 3GLs. The term 4GLs is closely associated with query languages and report generators. Source: Alter 1999

Other Major Developments in Programming
Special-Purpose Languages Spreadsheets Computer Aided Software Engineering (CASE) Systems Source: Alter 1999

Special Purpose Languages
Languages that are related to the area of business or the type of problem in question. Examples: modeling languages. simulation languages. Source: Alter 1999

CASE Systems CASE is the use of computerized tools to improve the efficiency, accuracy, and completeness of the process of analyzing, designing, developing and maintaining an information system. Classification: Upper CASE - logical modeling. Lower CASE - code generation. Source: Alter 1999

Operating Systems Complex programs that control the operation of computers and networks by controlling execution of other programs running on the computer, communication with peripheral devices including terminals, and use of disk space and other computer system resources. Source: Alter 1999

OS functions affecting a PC user
Controlling the user interface. Controlling tasks in progress. support for multitasking. Controlling access to data. password access to restricted data. Allocating resources. allocation of memory and disk space. Source: Alter 1999

OS for Multi-User Computer Systems
Run many jobs simultaneously for different users, taking priority into account. Make sure that the users, their data, and their various jobs do not interfere with each other. Maintain computer system security. Source: Alter 1999

OS for Multi-User Computer Systems
Network operating system establishes the links between nodes, monitors network operation, and controls recovery processes when needed. Must work in conjunction with OS for the individual workstations on the network. Source: Alter 1999

Examples of Multi-User OS
IBM’s MVS and Digital’s VMS UNIX IBM’s AIX, HP/UX, Sun’s Solaris, Digital’s UNIX, SCO’s UNIX etc. Microsoft’s Windows NT Source: Alter 1999

The Enterprise Alphabet Soup
1980s - JIT, TQM, MRP II, CIM 1990s - Convergence of TQM, Re-Engineering, Benchmarking, Change Management and Strategic Planning. NOW - Convergence of Total Customer Experience, Network-Centric Enterprise, Virtual and Agile Enterprise, Knowledge Based Enterprise and Service Based Enterprise.

Traditional Enterprise
Vertically Integrated Self-sufficient; converted raw materials to finished goods. Tight coordination among processes. Examples are, early automobile and computer firms.

Virtual Enterprises Concentrate on core competencies.
Focus on processes at which the enterprise can excel or be world-class. Partner companies perform other processes. Examples CISCO concentrates on new product development and sales. Auto manufacturers focus on vehicle design and final assembly.

Virtual Integration New organization model for the information age.
Harnesses the benefits of two different business models. Coordination of a vertically integrated enterprise. Focus and specialization that drive virtual enterprises.

Vertical Integration Use of technology and information to blur the traditional boundaries and roles in the value chain - suppliers, manufacturer and end users. New levels of efficiency and productivity. Example - Dell’s direct business model.

Dell’s Direct Business Model
Bypass dealer channels. Directly to customer and build product to order. Eliminated reseller’s markup. Eliminated risks and costs associated with large finished goods inventory. Focus is on delivering solutions and systems to customers.

Virtual Integration Combines pieces of contemporary business strategy in a unique way Customer focus, supplier partnership, mass customization, just-in-time manufacturing. Stitching together a business with partners that are treated as if they are inside the company.

Virtual Integration Partnerships vs. Outsourcing.
Dell sets quality measures and builds data-linkages with partners to monitor performance. Partners become part of the company. As few partners as possible. Partners must maintain leadership in technology and quality.

Virtual Integration Information shared with business partners in a real time fashion. Share daily production requirements with suppliers. Share design databases and methodologies with suppliers. Time to market is dramatically reduced.

Virtual Integration Challenges in establishing supplier collaborations
Changing focus from how much inventory to how fast it is moving. Inventory velocity is a key performance measure. Long-term contracts just-in-time delivery. Example, Sony monitors for Dell computers.

Virtual Integration Substitute information for inventory.
Ship only when there is real demand from real customers. Traditional model (computer industry) stack up units in warehouse and then in channel. Stuff channel to get rid of old inventory.

Virtual Integration Partnerships with customers
Customer segmentation is an important element of Dell’s virtual integration with customers. Segmentation takes the company closer to the customer. Better understanding of customer’s needs. Ability to produce better forecasts. Reduced inventories.

Vertical Vs. Virtual Integration
Vertical integration allows a company to be efficient under stable conditions. Virtual integration allows a company to be efficient and responsive to change at the same time.

Value Webs Forces Reshaping Value Chains
Peripheral changes in the roles of value chain members Customer/Consumer preference for personal customization These forces morph value chains to value webs

Value Chains Vs. Value Webs
Value chains do not motivate their members to develop an integrated infrastructure. Value webs promote a fully integrated infrastructure that links together all the members.

Value Web Management (VWM)
A model of infrastructure that is capable of supporting the value webs. Produced by the marriage of business and technical infrastructure. An extension of the old Supply Chain Management.

VWM Allows value web members to exchange critical information/knowledge in real time and synchronize their efforts to respond and produce the desired results also in real time.

VWM and SCM SCM promotes logistics as the key mechanism to link the individual members of the value chain. VWM promotes one integrated business system.

Key Concepts Information/Knowledge: Value Web collects, archives, retrieves, creates, shares, and otherwise leverages information that can be translated into knowledge and wisdom. Real Time: The best enterprises must manage their business in real time because of the dynamic and fast paced environment in which they operate.

Guiding Principles of the Value Web
Disintermediation: the removal of any intermediary node in the value web; a synonym for value chain collapse. Reintermediation: change in role of any intermediary to better serve the value web. Infomediation: the addition of new information/knowledge-based intermediaries.

Role Transformation: changes in the roles of value web members, individually and as a whole. Dematerialization: the conversion of materials and material-related assets to bits and bytes.

Digitization: capturing all pertinent information/knowledge for the value-web members to be used efficiently, effectively and interactively. Resource Exploitation: leveraging certain pre-specified skills, capabilities, competencies, assets, structures, and infrastructures of others within the value web.

Reference Articles Andrews, P. P. and J. Hahn (199), Transforming Supply Chains into Value Webs, Strategy & Leadership. pp Magretta, J. (1998), The Power Of Virtual Integration: An Interview With Dell Computer's Michael Dell, Harvard Business Review. pp Hammer, M. (2000), The Rise Of The Virtual Enterprise. Information Week. pp. 152.

Source: Andrews and Hahn 1999
Value Webs Forces Reshaping Value Chains Peripheral changes in the roles of value chain members Customer/Consumer preference for personal customization These forces morph value chains to value webs Source: Andrews and Hahn 1999

Value Chains Vs. Value Webs
Value chains do not motivate their members to develop an integrated infrastructure. Value webs promote a fully integrated infrastructure that links together all the members. Source: Andrews and Hahn 1999

Value Web Management (VWM)
A model of infrastructure that is capable of supporting the value webs. Produced by the marriage of business and technical infrastructure. An extension of the old Supply Chain Management. Source: Andrews and Hahn 1999

VWM Allows value web members to exchange critical information/knowledge in real time and synchronize their efforts to respond and produce the desired results also in real time. Source: Andrews and Hahn 1999

VWM and SCM SCM promotes logistics as the key mechanism to link the individual members of the value chain. VWM promotes one integrated business system. Source: Andrews and Hahn 1999

Key Concepts Information/Knowledge: Value Web collects, archives, retrieves, creates, shares, and otherwise leverages information that can be translated into knowledge and wisdom. Real Time: The best enterprises must manage their business in real time because of the dynamic and fast paced environment in which they operate. Source: Andrews and Hahn 1999

Disintermediation: the removal of any intermediary node in the value web; a synonym for value chain collapse. Reintermediation: change in role of any intermediary to better serve the value web. Infomediation: the addition of new information/knowledge-based intermediaries. Source: Andrews and Hahn 1999

Role Transformation: changes in the roles of value web members, individually and as a whole. Dematerialization: the conversion of materials and material-related assets to bits and bytes. Source: Andrews and Hahn 1999

Digitization: capturing all pertinent information/knowledge for the value-web members to be used efficiently, effectively and interactively. Resource Exploitation: leveraging certain pre-specified skills, capabilities, competencies, assets, structures, and infrastructures of others within the value web. Source: Andrews and Hahn 1999

Business Processes Architectural characteristics that affect business process performance Evaluating business process performance Role and value of information systems Source: Alter 1999

Architectural Characteristics
Degree of structure degree of predetermined correspondence between inputs and outputs of a process structured, semi structured, and unstructured tasks using information systems to impose different degrees of structure on business processes Source: Alter 1999

Imposing Structure on Work
Highest Level: Substitution of technology for people Replace the person with technology ATM Automate much of the work Computer programs Source: Alter 1999

High Level: Enforcement of rules or procedures Control each step in the work Loan approval system of a bank using a fill-in-the-blanks form Provide real-time guidance for work steps performed by people An interactive shop-floor control system Source: Alter 1999

Low Level: Access to information or tools Use a model to evaluate or optimize a potential decision. Model to help the allocation of funds Provide specialized tools that help people do their work A CAD system Source: Alter 1999

Low Level: Access to information or tools Provide information that is filtered, formatted, and summarized to make it useful. An MIS Provide a general purpose tool to help people do work. A telephone, spreadsheet or word processor Source: Alter 1999

Range of involvement - the organization span of people involved in a business processes too many participants or too few information systems can broaden or constraint the range of involvement in a business process Doers vs. checkers Source: Alter 1999

Integration - mutual responsiveness and collaboration between distinct activities or processes extent of integration between two processes or activities is related to the speed at which one responds to events in the other five levels of integration Source: Alter 1999

Levels of integration Common culture Common standards
shared understandings and beliefs Common standards using consistent terminology and procedures to make business processes easier to maintain and interface Information sharing access to each other’s data by business processes that operate independently. Source: Alter 1999

Levels of integration Coordination Collaboration
negotiation and exchange of messages permitting separate but interdependent processes to respond to each other’s needs and limitations Collaboration such strong interdependence that the unique identity of separate processes begins to disappear Source: Alter 1999

Complexity a combination of how many types of elements a system contains and the number and nature of their interactions. Degree of reliance on machines assign tasks to people and machines in a way that emphasizes strengths and de-emphasizes the weakness of each. Source: Alter 1999

Attention to planning execution, and control what to do, when to do it, and how to make sure it is done properly Treatment of exceptions, errors and malfunctions especially important is computerized business processes Source: Alter 1999

Information Issues Related to Planning and Execution
Planning (Future) Having reliable methods of projecting into the future by combining models, assumptions, and data about the past and present Execution (Present) Providing new information to make adjustments Using current information to identify problems or errors Collecting information Source: Alter 1999

Information Issues Related to Control
Control (Past) Having reliable methods of using past data to develop or adjust plans Providing real-time information to guide current actions Source: Alter 1999

Performance Variables and Related Roles of IS
Rate of output - average units per hour or week; peak load units per hour or week increase rate of output by performing some of the work automatically increase rate of output by systematizing the work Source: Alter 1999

Productivity - output per labor hour or machine hour; ratio of output to input (in dollars); scrap rate; Cost of rework help people produce more output with the same effort automate data processing functions systematize work to reduce waste schedule work to improve resource utilization Source: Alter 1999

Consistency - defect rate; percentage variation; rework rate systematize work to reduce variability of the product Provide immediate feedback to identify and correct errors Help process participants analyze the causes of defects Source: Alter 1999

Cycle time - elapsed time from start to finish; total WIP inventory divided by weekly output perform data processing work more quickly make it possible to combine steps make it possible to perform steps in parallel, thereby eliminating delays systematize work to reduce waste Source: Alter 1999

Flexibility - number of possible product variations; ease of customizing to customer specifications systematize the form and content of product specifications to make it easier to handle variations make it possible to control the process based on specifications that can be entered through a computer Source: Alter 1999

Security - number of process breaches in a time interval; seriousness of process breaches in a time interval systematize record-keeping about business process systematize record-keeping about computer access and usage track all nonstandard transactions such as changes to completed transactions Source: Alter 1999

INFORMATION SYSTEMS AND TECHNOLOGY

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