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Chapter 10 Information Systems Development. Q1: What is systems development? Q2: Why is systems development difficult and risky? Q3: What are the five.

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Presentation on theme: "Chapter 10 Information Systems Development. Q1: What is systems development? Q2: Why is systems development difficult and risky? Q3: What are the five."— Presentation transcript:

1 Chapter 10 Information Systems Development

2 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? Study Questions 10-2

3 Video Process of creating and maintaining information systems Involves all five IS components Q1: What Is Systems Development? 10-3 See author video

4 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. Q2: Why Is Systems Development Difficult and Risky? 10-4

5 Five Major Challenges to Systems Development 10-5

6 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. Q2: Why Is Systems Development Difficult and Risky? (cont’d) 10-6

7 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? Q2: Why Is Systems Development Difficult and Risky? (cont’d) 10-7

8 Changing Technology Q2: Why Is Systems Development Difficult and Risky? (cont’d) 10-8 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 Diseconomies of scale Brooks’ Law “Adding more people to a late project makes the project later.” Q2: Why Is Systems Development Difficult and Risky? (cont’d) 10-9 New staff must be trained by productive members who lose productivity while training new members. A later project costs more and increases the unit price.

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

11 Q3: What Are the Five Phases of the SDLC?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 10-13

14 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 Define scope for new Fox Lake system Q4: How Is System Definition Accomplished? (cont’d) 10-14

15 Cost feasibilityCost feasibility (economic feasibility) Approximated, “back-of-the-envelope” analysis Purpose: eliminate infeasible ideas early Consider cost of previous projects, operational and labor costs Schedule feasibilitySchedule 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 Assess Feasibility: Dimensions of Feasibility 10-15

16 Typical team Systems analyst and/or business analyst Managers Programmers Software testers Users Team composition changes over time Active user involvement is critical throughout Form a Project Team 10-16

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

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

19 Figure 10-7 Procedures to Be Designed 10-19

20 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 Design of Job Descriptions 10-20

21 How Is an Information System Implemented? Q7: How Is an Information System Implemented? Building 2.Testing 3.Converting

22 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 ( external user acceptance ) Q7: How Is an Information System Implemented? (cont’d) 10-22

23 Design and Implementation for the Five IS Components 10-23

24 System Conversion Approaches Pilot Implement entire system in limited portion of business Advantage: Limits exposure to business if system fails Phased System installed in phases or modules Each piece is installed and tested Parallel Complete new and old systems run simultaneously Very safe, but expensive, time consuming Plunge Plunge (“Big Bang”) High risk if new system fails, no fall back system Only used if new system not vital to company operation

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 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 Business requirements change “Analysis paralysis”—projects spend so much time on documentation it hampers progressAnalysis paralysis Requirements documentation difficulty 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 Q9: What Are Some of the Problems with the SDLC? 10-26

27 SDLC Waterfall Method vs. RAD 10-27

28 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) The ERP Implementation Method at Cisco 10-28

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?

30 Suppose that you and two or three other students have been groundskeepers at Fox Lake, and you have decided to go out on your own and open a business that offers landscaping services. Your goal is to develop a list of clients for whom you provide regular and recurring services, such as mowing, weeding, and pool cleaning, as well as specialty services, such as pruning, garden preparation, tree removal, sprinkler installation and repair, and the like. Need information system for tracking customers, services you have provided, and services you are scheduled to provide in the future. As a new small business, you want a simple and affordable system based on Excel or Access. The name of the system is GardenTraker. Experiencing MIS InClass Exercise 10: GardenTraker 10-30

31 1. Explain how you would use the SDLC to develop GardenTraker. 2. Define the scope of your system. 3. Explain the process you would use to determine the feasibility of GardenTraker. List data you need for such an assessment, and explain how you might obtain or estimate that data. Experiencing MIS InClass Exercise 10: GardenTraker (cont’d) 10-31

32 4.Consider just the tracking of recurring services, and list all of the requirements that you can imagine for that functionality. Be specific and answer at least the following: a.What data will you need? b.How will you input that data? Show a mockup of a data entry screen, and describe how it will be used. c.Using your mockup, describe how you will modify recurring service data. d.Using your mockup, describe how you will cancel a recurring service. e.Specify any other requirements you believe are important for tracking recurring services. Experiencing MIS InClass Exercise 10: GardenTraker (cont’d) 10-32

33 5.Present your answers to item 4 to the rest of the class and obtain feedback from your classmates. 6. Modify your answer to item 4 based upon feedback you received in item Considering just the recurring services functionality, do you think it would be better to use Excel or Access for this project? List the criteria you used to answer that question. Summarize the consequences of making a poor choice between these two products. 8. What does this short exercise tell you about information systems development? Answer this question in such a way that you could use your answer to demonstrate your critical-thinking skills in a job interview Experiencing MIS InClass Exercise 10: GardenTraker (cont’d) 10-33


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