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Chapter 8: Systems Development Please turn your cell phone off.
Topics: Systems Investigation Systems Analysis Systems Design Systems Implementation Systems Maintenance and Review Please turn your cell phone off.
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Systems Development Life Cycle
Intelligence Stage Design Stage Choice Stage Implementation Monitoring Problem Solving
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An Overview of Systems Development
Chapter 8.1 An Overview of Systems Development Key Terms Stakeholders Users Systems analyst Programmer Information systems planning
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Participants in Systems Development
Effective systems development requires a team effort.
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Participants Stakeholders Users Systems analyst Programmer
People who benefit from the systems development project Users People who will interact with the system regularly Systems analyst Person who specializes in analyzing and designing business systems Programmer Person responsible for modifying or developing programs to satisfy user requirements
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Information Systems Planning
The translation of strategic and organizational goals into system development initiatives. Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals.
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Importance of IS Planning
Figure 8.3: The Steps of IS Planning
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Systems Development Life Cycle
Chapter 8.2 Systems Development Life Cycle Key Terms Systems investigation Systems analysis Systems design Systems implementation Systems maintenance and review Prototyping Rapid application development (RAD) Joint application development (JAD) End-user systems development Computer-aided software engineering (CASE) Object-oriented systems development (OOSD)
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The Traditional Systems Development Life Cycle
Figure 8.4: The Traditional Systems Development Life Cycle
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The Traditional Systems Development Life Cycle
Systems investigation: problems and opportunities are identified and considered in light of the goals of the business Systems analysis: study of existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement Systems design: defines how the information system will do what it must do to obtain the problem’s solution
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The Traditional Systems Development Life Cycle
Systems implementation: the creation or acquiring of various system components detailed in the systems design, assembling them, and placing the new or modified system into operation Systems maintenance and review: ensures that the system operates, and modifies the system so that it continues to meet changing business needs
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Prototyping Prototyping Iterative approach to system design
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RAD & JAD Rapid application development (RAD): a systems development approach that employs tools, techniques, and methodologies designed to speed application development Joint application development (JAD): a process for data collection and requirements analysis in which users, stakeholders, and IS professionals work together to analyze existing systems, propose possible solutions, and define the requirements for a new or modified system
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The 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 End-user-developed systems can be structured as complementary to, rather than in conflict with, existing and emerging information systems
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Use of Computer-Aided Software Engineering (CASE) Tools
Tools that automate many of the tasks required in a systems development effort and enforce adherence to the SDLC
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Use of Computer-Aided Software Engineering (CASE) Tools
Table 8.2: Advantages and Disadvantages of CASE Tools
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Object-Oriented Systems Development
OOSD The approach that combines the logic of the systems development life cycle with the power of object-oriented modeling and programming. Object-oriented systems development typically involves: Identifying potential problems and opportunities within the organization that would be appropriate for the OO approach Defining the kind of system users require Designing the system
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Object-Oriented Systems Development
Object-oriented systems development typically involves (continued): Programming or modifying modules Evaluation by users Periodic review and modification
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Systems Investigation
Chapter 8.3 Systems Investigation Key Terms Systems request form Feasibility analysis Technical feasibility Economic feasibility Legal feasibility Operational feasibility Schedule feasibility Systems investigation report
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Systems Investigation
Identify potential problems and opportunities and consider them in light of the goals of the company. Formal procedures for initiating systems development typically include a Systems Request Form: Identifies problems in or opportunities for the system States objectives of systems investigation Presents an overview of the proposed system Projects expected costs and benefits of the proposed system
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Feasibility Analysis Feasibility analysis is the assessment of the technical, economic, legal, operational, and schedule feasibility of a project Technical feasibility Economic feasibility Legal feasibility Operational feasibility Schedule feasibility
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Feasibility Analysis Systems investigation report
A summary of the results of the systems investigation and the process of feasibility analysis and recommendations of a course of action.
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The Systems Investigation Report
Figure 8.8: A Typical Table of Contents for a Systems Investigation Report
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Systems Analysis Key Terms Chapter 8.4 Requirements analysis
Asking directly Structured interview Unstructured interview Direct observation Questionnaires Data analysis Data-flow diagram (DFD)
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Systems Analysis Data Collection Data Analysis
Seeks additional information about problems or needs. Internal and External Sources Data Analysis Data Modeling with entity-relationship diagrams Activity Modeling with data-flow diagrams
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Data Collection Identifying sources of data Collecting data
Internal sources External sources Collecting data Interviews Direct observation Questionnaires
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Data Collection Figure 8.9: Internal and External Sources of Data for Systems Analysis
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Collecting Data Structured interviews Unstructured interviews
Questions are written in advance Unstructured interviews Questions are not written in advance Direct observation Watching the existing system in action by one or more members of the analysis team
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Data Analysis Questionnaires Data modeling Activity modeling
Gathering data when the data sources are spread over a wide geographic area Data modeling Entity-relationship (ER) diagrams Activity modeling Data-flow diagrams (DFDs) A model of objects, associations, and activities by describing how data can flow between and around various objects
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Data Analysis Figure 8.11: Data and Activity Modeling (a) An entity-relationship diagram
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Data Analysis Figure 8.11: Data and Activity Modeling (continued) (b) A data-flow diagram
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Data Analysis Figure 8.11: Data and Activity Modeling (continued) (c) A semantic description of the business process
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Requirements Analysis
Determination of user, stakeholder, and organizational needs Asking directly An approach to gather data that asks users, stakeholders, and other managers about what they want and expect from the new or modified system
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Object-Oriented Systems Analysis
Identifying problems or potential opportunities Identifying key participants and collecting data Instead of analyzing the existing system using data-flow diagrams and flowcharts, an object-oriented approach is used
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Object-Oriented Systems Analysis
Figure 8.13: Generalization/Specialization Hierarchy Diagram for Single and Tandem Kayak Classes
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Systems Design Key Terms Chapter 8.5 Logical design Physical design
Request for proposal (RFP) Design report
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Systems Design Answers question “How will the information system solve a problem?” Logical Design Description of the functional requirements of a system Physical Design Specification of the characteristics of the system components necessary to put the logical design into action
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Systems Design Alternatives
Request for Proposal (RFP) A document that specifies in detail required resources such as hardware and software Sent to outside vendors
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The Design Report Design report: the result of systems design
Contains system specifications System specifications include technical description of: System outputs, inputs, and user interfaces Hardware, software, databases, telecommunications, personnel, and procedure components and the way these components are related
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The Design Report Figure 8.17: A Typical Table of Contents for a Systems Design Report
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Systems Implementation
Chapter 8.6 Systems Implementation Key Terms Make-or-buy decision Site preparation Data preparation or data conversion Installation Start-up Direct conversion (AKA Plunge or direct cutover) Phase-in approach, or piecemeal approach Pilot start-up Parallel start-up User acceptance document
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Systems Implementation
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Acquiring Software: Make or Buy?
Externally developed software In-house developed software Blend of external and internal software development Renting software Reusing software from other development efforts
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Site Preparation Preparation of the location of a new system
Making room for a computer in an office Special wiring and air conditioning Special flooring Additional power circuits
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Data Preparation Also called data conversion
Ensuring all files and databases are ready to be used with new computer software and systems
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Installation The process of physically placing the computer equipment on the site and making it operational Normally the manufacturer is responsible for installing computer equipment Someone from the organization (usually the IS manager) should oversee the process
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Start-Up The process of making the final tested information system fully operational Direct conversion (also called plunge or direct cutover) The process of stopping the old system and starting the new system on a given date Phase-in approach Slowly replacing components of the old system with those of the new one
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Start-Up Pilot start-up Parallel start-up
The process of running the new system for one group of users rather then for all users Parallel start-up The process of running both the old and new systems for a period of time, comparing the new system’s output with the old system’s, reconciling any differences, and finally eliminating the old system
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Start-up
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User Acceptance User-acceptance document: formal agreement signed by the user that states that a phase of the installation or the complete system is approved
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Systems Operation & Maintenance
Chapter 8.7 Systems Operation & Maintenance Key Terms Systems operation
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Systems Operation and Maintenance
Systems operation: use of a new or modified system Systems maintenance: checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals
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Systems Maintenance Reasons for the need of Maintenance:
Bugs or errors in the program New requests from users and stakeholders Technical and hardware problems Change in operating system or hardware Changes in business processes Corporate mergers and acquisitions Government regulations (HIPAA)
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Systems Review Key Terms Chapter 8.8 Event-driven review
Time-driven review
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Systems Review Process of analyzing systems to make sure that they are operating as intended Often compares the performance and benefits of the system as it was designed with the actual performance and benefits of the system in operation Event-driven review: review triggered by a problem or opportunity, such as an error, a corporate merger, or a new market for products Time-driven review: review performed after a specified amount of time
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