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Introduction to Systems Development Life Cycle

Introduction to Systems Development Life Cycle. The Information Systems Life Cycle. What are the four steps in the information systems life cycle (ISLC)? System development System implementation Syetem Operation System obsolencence. The Systems Development Life Cycle.

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Introduction to Systems Development Life Cycle

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  1. Introduction to Systems Development Life Cycle

  2. The Information Systems Life Cycle • What are the four steps in the information systems life cycle (ISLC)? • System development • System implementation • Syetem Operation • System obsolencence

  3. The Systems Development Life Cycle • What are the five steps in the systems development life cycle (SDLC)? • Systems analysis • Conceptual design • Physical design • Implementation and conversion • Operations and maintenance

  4. The Systems Development Life Cycle: Systems Analysis Systems Analysis Do initial investigation Do system survey Do feasibility study Determine information needs and system requirements Deliver systems requirements Conceptual Design

  5. The Systems Development Life Cycle: Conceptual Design Conceptual Design Identify and evaluate design alternatives Develop design specifications Deliver conceptual design requirements Physical Design

  6. The Systems Development Life Cycle: Physical Design Physical Design Design output Design database Design input Develop programs Develop procedures Design controls Deliver developed system Implementation and Conversion

  7. The Systems Development Life Cycle: Implementation and Conversion Implementation and Conversion Develop plan Install hardware and software Train personnel, test the system Complete documentation Convert from old to new system Fine-tune and review Deliver operational system Operation and Maintenance

  8. The Systems Development Life Cycle: Operation and Maintenance Feasibility analysis and decision points: Economic Feasibility Technical Feasibility Legal Feasibility Scheduling Feasibility Operational Feasibility Operation and Maintenance Operate system Modify system Do ongoing maintenance Deliver improved system Systems Analysis

  9. The Players • Who are the people involved in developing and implementing IS? • Management • Information systems steering committee • Project development team • Systems analysts and programmers • External players

  10. The Players • What are top management’s roles? • providing support and encouragement • establishing system goals and objectives • determine information requirements

  11. The Players • What are the steering committee’s roles? • set policies that govern the IS • ensures top-management participation • guidance and control • facilitates coordination and integration of IS activities

  12. The Players • What are the project development team’s roles? • plan each project • monitor project • make sure proper consideration is given to the human element

  13. The Players • What are the system analyst’s and programmer’s roles? • study existing systems • design new systems and prepare specifications • write computer programs

  14. Planning Systems Development • Why is planning an important step in systems development? • consistency • efficiency • cutting edge • lower costs • adaptability

  15. Planning Systems Development • What types of systems development plans are needed? • project development plan • master plan

  16. Planning Techniques • Two techniques for scheduling and monitoring systems development activities are: • PERT (program evaluation and review technique) • PERT requires that all activities and the precedent and subsequent relationships among them be identified. • Gantt chart • A bar chart with project activities listed on the left-hand side and units of time across the top

  17. Planning Techniques: Gantt Chart Project Planning Chart (Sample Gantt Chart) ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Activity Week Starting 1 2 3 4 5 6 7 8

  18. Gantt Chart

  19. PERT Chart

  20. Microsoft Project Gantt Chart

  21. Microsoft Project PERT Chart

  22. Feasibility Analysis • Systems analysis is the first step in the systems development life cycle (SDLC). • A feasibility study(also called a business case) is prepared during systems analysis and updated as necessary during the remaining steps in the SDLC. • The steering committee uses the study to decide whether to terminate a project, proceed unconditionally, or proceed conditionally.

  23. Feasibility Analysis • What five important aspects need to be considered during a feasibility study? • Technical feasibility • Operational feasibility • Legal feasibility • Scheduling feasibility • Economic feasibility

  24. Feasibility Analysis • Economic feasibility is the most frequently analyzed of the five aspects. • What is the basic framework for feasibility analysis? • capital budgeting model

  25. Feasibility Analysis • What are some capital budgeting techniques? • payback period • net present value (NPV) • internal rate of return (IRR)

  26. Candidate Systems Matrix

  27. Candidate Systems Matrix (cont.)

  28. Feasibility Matrix

  29. Typical System Proposal Outline • Introduction • Purpose of the report • Background of the project leading to this report • Scope of the report • Structure of the report • Tools and techniques used • Solution generated • Feasibility analysis (cost-benefit) • Information systems requirements • Alternative solutions and feasibility analysis • Recommendations • Appendices

  30. Behavioral Aspects of Change • Individuals involved in systems development are agents of change who are continually confronted by people’s reaction and resistance to change. • The best system will fail without the support of the people it serves.

  31. Behavioral Aspects of Change • Why do behavioral problems occur? • personal characteristics and background • manner in which change is introduced • experience with prior changes • communication • disruptive nature of the change process • fear

  32. Behavioral Aspects of Change • How do people resist IS changes? • aggression • projection • avoidance

  33. Behavioral Aspects of Change • How can behavioral problems be overcome? • meet needs of the users • keep communication lines open • maintain a safe and open atmosphere • obtain management support • allay fears • solicit user participation • make sure users understand the system

  34. Behavioral Aspects of Change • How can behavioral problems be overcome? (continued) • provide honest feedback • humanize the system • describe new challenges and opportunities • reexamine performance evaluation • test the system’s integrity • avoid emotionalism • present the system in the proper context • control the users’ expectations • keep the system simple

  35. Systems Analysis • When a new or improved system is needed, a written request for systems developmentis prepared. • The request describes the current system’s problems, why the change is needed, and the proposed system’s goals and objectives. • It also describes the anticipated benefits and costs.

  36. Sample Request for System Services

  37. Sample Problem Statements

  38. Systems Analysis • There are five steps in the analysis phase: • Initial investigation • Systems survey • Feasibility study • Information needs and systems requirements • Systems analysis report

  39. Computer-Aided Software Engineering (CASE) • CASE is an integrated package of computer-based tools that automate important aspects of the software development process. • CASE tools are used to plan, analyze, design, program, and maintain an information system. • They are also used to enhance the efforts of managers, users, and programmers in understanding information needs.

  40. Computer-Aided Software Engineering (CASE) • CASE tools do not replace skilled designers; instead they provide a host of self-integrated tools that give developers effective support for all SDLC phases. • CASE software typically has tools for strategic planning, project and system management, database design, screen and report layout, and automatic code generation.

  41. CASE Tool Architecture

  42. Computer-Aided Software Engineering (CASE) Advantages of CASE Technology Improved productivity Improved program quality Cost savings Improved control procedures Simplified documentation

  43. Computer-Aided Software Engineering (CASE) Disadvantages of CASE Technology Incompatibility Cost Unmet expectations

  44. Systems Design, Implementation, and Operation

  45. Conceptual Systems Design • In the conceptual systems design phase, a general framework is developed for implementing user requirements and solving problems identified in the analysis phase. • What are the three steps in conceptual design? • Evaluate design alternatives. • Prepare design specifications. • Prepare conceptual systems design report.

  46. Conceptual Systems Design Systems analysis Evaluate design alternatives Prepare design specifications Prepare conceptual systems design report

  47. Conceptual Systems Design • Evaluate design alternatives: • The design team should identify and evaluate design alternatives using the following criteria: • How well it meets organizational and system objectives • How well it meets users’ needs • Whether it is economically feasible • Its advantages and disadvantages

  48. Conceptual Systems Design • Prepare design specifications: • Once a design alternative has been selected, the team develops the conceptual design specificationsfor the following elements: • Output • Data storage • Input • Processing procedures and operations

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