Chapter 3

1. Chapter 3 Requirements Modeling

2. Phase Description • Systems analysis is the 2nd of 5 phases in the systems development life cycle (SDLC) • Uses requirements modeling and enterprise modeling to represent the new system • Before proceeding to the next phase, systems design, consider some system development strategies

3. Chapter Objectives • Describe systems analysis phase activities and the end product, system requirements document • Understand joint application development (JAD) and rapid application development (RAD) • List and describe system requirements, including outputs, inputs, processes, performance, and controls • Explain the importance of scalability in system design

4. Chapter Objectives • Define total cost of ownership (TCO) and explain the concept • Conduct a successful interview • Develop effective documentation methods to use during systems development

5. Introduction • Requirements modeling techniques (fact-finding) and team-based methods (JAD/RAD) are tools that systems analysts use to visualize and document new systems • System requirements and fact-finding techniques are interviewing, documentation review, observation, surveys and questionnaires, sampling, and research

6. Systems Analysis Phase Overview • Uses models and other documentation tools to visualize and describe the proposed system • The deliverable is a system requirements document Figure 3-2

7. Systems Analysis Phase Overview • Systems Analysis Skills • Analytical skills • Interpersonal skills • Team-Oriented Methods & Techniques • Joint application development (JAD) (user involved) • Rapid application development (RAD) (mini SDLC)

8. Joint Application Development • User Involvement • Users have a vital stake in an information system and they should participate fully • Successful systems must be user-oriented and users need to be involved

9. Joint Application Development • JAD Advantages and Disadvantages • More expensive and can be cumbersome • Allows key users to participate effectively • When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system.

10. Rapid Application Development • Is a team-based technique that speeds up information systems development and produces a functioning information system • Relies heavily on prototyping and user involvement • Project team uses CASE tools to build the prototypes and create a continuous stream of documentation

11. Rapid Application Development • RAD Objectives • To cut development time and expense by involving the users in every phase of systems development • Successful RAD team must have IT resources, skills, and management support • Helps a development team design a system that requires a highly interactive or complex user interface

12. Rapid Application Development • RAD Advantages and Disadvantages • Systems can be developed more quickly with significant cost savings • RAD stresses the mechanics of the system itself and does not emphasize the company’s strategic business needs • Might allow less time to develop quality, consistency, and design standards

13. Modeling Tools and Techniques • Unified Modeling Language • A widely used method of visualizing and documenting software systems design • provides various graphical tools and techniques, such as use case diagrams and sequence diagrams

14. Modeling Techniques • Functional Decomposition Diagrams • A top-down representation of business functions and processes • Also called structure charts

15. Modeling Techniques • Functional Decomposition Diagrams Figure 3-9

16. System Requirements Checklist • System requirement • Five general categories • Outputs • Inputs • Processes • Performance • Controls

17. Future Growth, Costs, and Benefits • Scalability • A scalable system offers a better return on the initial investment • To evaluate, you need information about projected future volume for all outputs, inputs, and processes

18. Future Growth, Costs, and Benefits • Total Cost of Ownership • In addition to direct costs, systems developers must identify and document indirect expenses that contribute to the total cost of ownership (TCO) • Formula: cost of design, cost of implementation, cost of editing, cost to replace • Plus number of users x days in year used x years before replaced x salary x extra time used per day. Plus lost customer good will, plus lost business.

19. Cost and Benefits • Tangible verses Intangible cost • Direct verses Indirect Costs • Fixed verses Variable Costs • Overhead Costs • Development verses Operational Costs • Profit verses Cost Center • Chargeback methods

20. Cost and Benefits • ROI – Return on Investment Benefit – costs = ratio % Total costs • Net Present Value Analysis NPV = total present value of benefits – total present value of costs (factored for inflation)

21. Fact-Finding • Overview • Although software can help you to gather and analyze facts, no program actually performs fact-finding for you • The first step is to identify the information you need

22. Fact-Finding • Who, What, Where, When, How, and Why?

23. Interview • Step 1: Determine the People to Interview • Informal structures • Step 2: Establish Objectives • Determine the general areas to be discussed • List the facts you want to gather

24. Interviews • Step 3: Develop Interview Questions • Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents • Avoid leading questions • Open-ended questions • Closed-ended questions • Range-of-response questions

25. Interviews • Step 4: Prepare for the Interview • Careful preparation is essential because an important meeting and not just a casual chat • Limit the interview to no more than one hour • Send a list of topics • Ask the interviewee to have samples available

26. Interviews • Step 5: Conduct the Interview • Develop a specific plan for the meeting • Begin with good introduction • Use engaged listening • Allow the person enough time to think about the question • Summarize main points • After interview, summarize the session and seek a confirmation

27. Interviews • Step 6: Document the Interview • During the interview, note taking should be kept to a minimum • After the interview, record the information quickly • After the interview, send memo expressing appreciation, including the main points discussed so the interviewee has a written summary and can offer additions or corrections

28. Interviews • Step 7: Evaluate the Interview • In addition to recording the facts obtained in an interview, try to identify any possible biases • Unsuccessful Interviews • No matter how well you prepare for interviews, some are not successful

29. Other Fact-Finding Techniques • Document Review • Observation • Seeing the system in action gives you additional perspective and a better understanding of the system procedures • Plan you observations in advance • Hawthorne Effect

30. Other Fact-Finding Techniques • Questionnaires and Surveys • Keep the questionnaire brief and user-friendly • Provide clear instructions that will answer all anticipated questions • Arrange the questions in a logical order, going from simple to more complex topics

31. Other Fact-Finding Techniques • Questionnaires and Surveys • Phrase questions to avoid misunderstandings; use simple terms and wording • Try not to lead the response or use questions that give clues to expected answers • Limit the use of open-ended questions that are difficult to tabulate

32. Other Fact-Finding Techniques • Questionnaires and Surveys • Limit the use of questions that can raise concerns about job security or other negative issues • Include a section at the end of the questionnaire for general comments • Test the questionnaire whenever possible on a small test group before finalizing it and distributing to a large group

33. Other Fact-Finding Techniques • Sampling • Systematic sample (every 10th customer for review) • Stratified sample (% of transactions/shift) • Random sample (any 20) • Main objective of a sample is to ensure that it represents the overall population accurately

34. Other Fact-Finding Techniques • Research • Newsgroups • Site visit Figure 3-23

35. Other Fact-Finding Techniques • Interviews versus Questionnaires • When you seek input from a large group questionnaire is a very useful tool • If you require detailed information from only a few people, then you probably should interview each person • Interview is more familiar and personal • Questionnaire gives many people the opportunity to provide input and suggestions

36. Documentation • The Need for Recording the Facts • Record information as soon as you obtain it • Use the simplest recording method • Record your findings in such a way that they can be understood by someone else • Organize your documentation

37. Documentation • Software Tools • CASE tools • Word processing • Spreadsheets • Databases Figure 3-24

38. Preview of Enterprise Modeling • At the conclusion of requirements modeling, systems developers should have clear understanding of business processes and system requirements • The next step is to model the logical design of the system

39. Chapter Summary • The systems analysis phase includes three activities • The main objective is to understand the proposed project and build a solid foundation for the systems design phase • The fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and research.

40. Chapter Summary • Systems analysts should carefully record and document factual information as it is collected, and various software tools can help an analyst visualize and describe an information system • Chapter 3 Complete