Chapter 15 Systems Development

2 Learning Objectives When you finish this chapter, you will  Understand the systems development life cycle.  Be able to list and explain the pros and cons of prototyping.  Understand how software tools facilitate the monitoring and controlling of systems development.

3 Learning Objectives  Recognize the difficulties involved in systems development.  Be able to list the advantages and disadvantages of different system conversion strategies.  Understand the concept of systems integration.

4 Why Develop an IS? Three phenomenon that trigger IS development  An opportunity (proactive)  A problem (reactive)  A directive

5 The Systems Development Life Cycle (SLDC) Figure 15.1 The systems development life cycle

6 The Systems Development Life Cycle (SLDC) Analysis  Determines what need the system will satisfy  Investigation  Developers interview managers and perspective users to determine business needs.  Three feasibility studies performed.

7 The Systems Development Life Cycle (SLDC) Figure 15.2 Phases in systems analysis

8 The Systems Development Life Cycle (SLDC)  The Technical Feasibility Study  Ensures hardware and software exist to build the system  The Economic Feasibility Study  Benefits of the system weighed against the cost  The Operational Feasibility Study  Determines if system will be used as intended  Requirements Definition  Specific requirements of system defined

9 The Systems Development Life Cycle (SLDC) Figure 15.3 Estimated benefits and costs of an IS ($)

10 The Systems Development Life Cycle (SLDC) Figure 15.4 Phases in systems design

11 The Systems Development Life Cycle (SLDC) Design  Logical Design  Translation of user requirements into detailed functions of the system  Physical Design  Construction  Systems Testing

12 The Systems Development Life Cycle (SLDC) Figure 15.5 Payroll system development. Using the divide- and-conquer approach, the planned system is broken into hierarchical modules.

13 The Systems Development Life Cycle (SLDC) Figure 15.6 A flowchart describing a sales bonus system

14 The Systems Development Life Cycle (SLDC) Figure 15.7 Data flow diagram symbols

15 The Systems Development Life Cycle (SLDC) Figure 15.8 The sales bonus system: a data flow diagram

16 The Systems Development Life Cycle (SLDC) Figure 15.9 Activities in systems implementation

17 The Systems Development Life Cycle (SLDC) Implementation  Training  Conversion  Parallel Conversion  Phased Conversion  Cold Turkey Conversion  Pilot Conversion

18 The Systems Development Life Cycle (SLDC) Figure Strategies used to convert from one IS to another

19 Figure Activities in systems support The Systems Development Life Cycle (SLDC) Support

20 Prototyping Systems developed using an iterative rather than a systematic process  Purpose is to develop a working model as quickly as possible, which can be tweaked and revised  Significantly shortens systems development backlog  Can increase risk of incompatibility and other unforeseen mishaps

21 Prototyping Figure In prototyping, refinement of the system continues until users are satisfied.

22 Prototyping Figure When to prototype and when not to prototype

23 Computer-Aided Software Engineering Computer-Aided Software Engineering (CASE tools)  System development programs that ease and speed design and construction of new ISs  Application generators  I-CASE tools  Rapid Application Development (RAD)

24 Project Management Project Management Tools  Project Evaluation and Review Technique (PERT)  PERT chart shows events, required activities, and relationships  Advantage: Communication of interdependencies among activities  Gantt Chart  Represents activities and start and completion times, but not the relationships among activities  Advantage: Simple and linear

25 Project Management Figure 15.14a Project management software allows managers to use both PERT charts (above) and Gantt charts (Figure 15.14b) to control projects.

26 Project Management Figure 15.14b Gantt chart

27 Project Management Figure Dimensions of project management

28 Project Management Project Management Goals  Complete the project on time.  Complete the project within budget.  Meet requirements.  Meet expectations.

29 Project Management Figure IS development projects: challenges and failures

30 Project Management Project Management Functions  Communication Management  Schedule Management  Quality Management  Financial Management  Resource Management

31 Systems Development Led by End Users JAD: An example of User-led Systems Development  Joint Application Development (JAD): method to be used in SDLU  Uses six-step process to take the team through planning and design

32 Systems Development Led by End Users Figure The six steps of JAD

33 Systems Development Led by End Users  JAD Critical Success Factors  All participants must be committed to JAD process.  Customers and IS people must agree on project’s scope.  Sponsor must be supportive and involved.  Team members must be empowered decision makers.  Business objectives must be clearly defined.  Business process must be understood.  Team members must be able to meet two or more days per week.  Members must be committed to the team.

34 Systems Integration Takes a look at the information needs of an entire organization (or a major division) Analysts integrate existing systems so that:  Data can flow more easily among business units.  Users can access different types of data via a single interface.

35 Ethical and Societal Issues Should IS Professionals Be Certified? Malfunctioning ISs  Faulty systems may wreak havoc, causing financial damage or even death  Should IS professionals be certified based on the high investment and risk involved in their work?

36 Ethical and Societal Issues Should IS Professionals Be Certified? Certification Pros  Protect potential employers  Protect clients of consultants  Fewer software-related failures Certification Cons  Difficult to measure software competence  May create a “closed shop:” decreased competition, decreased incentive to improve skills