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Information Systems Development

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  1. Chapter 10 Information Systems Development

  2. Study Questions Q1: What is systems development? Q2: Why is systems development difficult and risky? Q3: What are the five phases of the SDLC? Q4: How is system definition accomplished? Q5: What is the users’ role in the requirements phase? Q6: How are the five components designed? Q7: How is an information system implemented? Q8: What are the tasks for system maintenance? Q9: What are some of the problems with the SDLC? How does the knowledge in this chapter help Fox Lake and you?

  3. Q1: What Is Systems Development? Video Process of creating and maintaining information systems Involves all five IS components See author video

  4. Q2: Why Is Systems Development Difficult and Risky? Many projects never finished. Those that finish often 200–300% over budget. Some projects finish within budget and schedule, but never satisfactorily accomplish their goals.

  5. Five Major Challenges to Systems Development

  6. Q2: Why Is Systems Development Difficult and Risky? (cont’d) Difficult to determine requirements • What specifically is system to do? • How does wedding planner use new system to reserve a room or building? • What does data entry screen look like? • How does planner add/reduce facilities once wedding scheduled? • What should system do when a wedding is cancelled? • Facility schedule system interface with accounting systems? How? • Does system need to reserve floor or refrigerator space in restaurant kitchen? Must create environment where difficult questions are asked and answered.

  7. Q2: Why Is Systems Development Difficult and Risky? (cont’d) Changing requirements • Large, long projects aim at moving target Scheduling and budgeting difficulties • How long to build it? • How long to create data model? • How long to build database applications? • How long to do testing? • How long to develop and document procedures? • How long for training? • How many labor hours? Labor cost? • What’s the rate of return on investment?

  8. Q2: Why Is Systems Development Difficult and Risky? (cont’d) Changing Technology Do you want to stop your development to switch to the new technology? Would it be better to finish developing according to the existing plan? Why build an out-of-date system? Can you afford to keep changing the project?

  9. Q2: Why Is Systems Development Difficult and Risky? (cont’d) • New staff must be trained by productive members who lose productivity while training new members. Diseconomies of scale • Brooks’ Law • “Adding more people to a late project makes the project later.” A later project costs more and increases the unit price.

  10. Is It Really So Bleak? Systems development is challenging, but solid methodologies exist that are successful when supported and managed properly. Yes and No Systems development life cycle (SDLC), most common process for systems development.

  11. Q3: What Are the Five Phases of the SDLC? Based on problem analysis and decision solving processes

  12. Q4: How Is System Definition Accomplished? • Team of users and IT professionals • Small business may hire consultant to work with managers and key employees • Fox Lake: Jeff, Laura, Mike, Anne, and other key employees will define system

  13. A Gantt Chart

  14. Q4: How Is System Definition Accomplished? (cont’d) Define scope for new Fox Lake system • Purpose: Increase revenue from wedding events • Goals: Eliminate or at least reveal schedule conflicts and improve maintenance tracking • Scope: Specify users or business processes that will be involved, or facilities, functions, events that will be involved

  15. Assess Feasibility: Dimensions of Feasibility Cost feasibility(economic feasibility) • Approximated, “back-of-the-envelope” analysis • Purpose: eliminate infeasible ideas early • Consider cost of previous projects, operational and labor costs Schedule feasibility and operational feasibility • Ball park estimate Technical feasibility • Do we have the hardware, software, personnel, expertise to complete project? Organizational feasibility (legal feasibility) • Fits customs, culture, charter, legal requirements of organization

  16. Form a Project Team Typical team • Systems analyst and/or business analyst • Managers • Programmers • Software testers • Users Team composition changes over time Active user involvement is critical throughout

  17. Q5: What Is the Users’ Role in the Requirements Phase? Review and approve requirements Laura only person with knowledge of systems development, she will work with development contractor to help specify Fox Lake’s needs

  18. Q6: How Are the Five Components of IS Designed? Determine hardware specifications • Purchase it, lease it, or lease time from hosting service Determine software specifications • Off-the-shelf, in-house developed, customized Procedure design • Normal, backup, and failure recovery procedures Database design Design Job Descriptions • Create and define new tasks and responsibilities • Convert data model to a database design

  19. Procedures to Be Designed • Figure 10-7

  20. Design of Job Descriptions Teams of systems analysts and users determine job descriptions and functions Duties and responsibilities for new jobs and revised jobs coordinated with human resources policies

  21. Q7: How Is an Information System Implemented? • Building • Testing • Converting

  22. Q7: How Is an Information System Implemented? (cont’d) System testing Test plan Product Quality Assurance (PQA vs. QAP) User testing • Develop test plans and test cases • Final say on whether system is “production ready” Alpha testing (internal acceptance), Beta testing (externaluser acceptance)

  23. Design and Implementation for the Five IS Components

  24. System Conversion Approaches

  25. Q8: What Are the Tasks for System Maintenance? Failure is a difference between what system does and what it is supposed to do.

  26. Q9: What Are Some of the Problems with the SDLC? • Sequence of non-repeated phases • It rarely works smoothly, causing development team to go back and forth, raising costs and delaying project SDLC Waterfall Method Requirements documentation difficulty • Business requirements change • “Analysis paralysis”—projects spend so much time on documentation it hampers progress • Time and cost estimates for large project usually way off • People who make initial estimates know little about how long it will take or cost Scheduling and budgeting difficulties

  27. SDLC Waterfall Method vs. RAD

  28. The ERP Implementation Method at Cisco • Rapid iterative prototyping • A series of phases “Conference room Pilots” (CRPs 0, 1, 2 and 3) • System Conversion Methods • Parallel(keeping the old system running alongside the new system for the first couple of weeks or months) • Direct(within a day or over a weekend or holiday period) • Pilot(using the new system in only a small section of the company) • Phased(taking offline parts of the old system and replacing them with the corresponding parts of the new system)

  29. Active Review Q1: What is systems development? Q2: Why is systems development difficult and risky? Q3: What are the five phases of the SDLC? Q4: How is system definition accomplished? Q5: What is the users’ role in the requirements phase? Q6: How are the five components designed? Q7: How is an information system implemented? Q8: What are the tasks for system maintenance? Q9: What are some of the problems with the SDLC? How does the knowledge in this chapter help Fox Lake and you?