COSC 2810 Systems Analysis and Design Phase 2 : Systems Analysis (Chapter 3, 4, 5)

1. COSC 2810 Systems Analysis and Design Phase 2 : Systems Analysis (Chapter 3, 4, 5) Chapter 3: Requirements Modeling Chapter 4: Enterprise Modeling Chapter 5: Development Strategies Chapter 3: Requirements Modeling • After system planning (Phrase 1), an sys. analyst needs to use requirements models to describe the new sys. This chapter describes modeling techniques and team-based methods to visualize and document the new sys.

2. Phase 2 System Analysis: • Systems analysis is the second of five 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, a sys. analyst will consider system development strategies

3. Chapter Objectives • Describe systems analysis phase activities and the end product of the systems analysis phase(A system requirements document) • Understand joint application development (JAD) and rapid application development (RAD) • Explain how systems analysts use a functional decomposition diagram (FDD) • Describe the Unified Modeling Language (UML) and use case diagrams and sequence diagrams

4. Chapter Objectives • List and describe system requirements, including outputs, inputs, processes, performance, and controls • Explain the importance of scalability in system design • Use fact-finding techniques, including interviews, documentation review, observation, questionnaires, sampling, and research

5. 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

6. Introduction • This chapter describes requirements modeling techniques and team-based methods that systems analysts use to visualize and document new systems • The chapter discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research

7. Systems Analysis Phase Overview • Use models and other documentation tools to visualize and describe the proposed system • The deliverable is a system requirements document • Sys. analysis phase includes 3 main activities: Figure 3-2

8. Systems Analysis Phase Overview • Requirement modeling involves fact-finding to describe the current sys. and identify the requirements of the new sys. • Systems Analysis Skills • Analytical skills(Id a problem,evaluate key elements of the problem, and develop a solution.) • Interpersonal skills (communicating people at all levels) • Team-Oriented Methods and Techniques • Joint application development (JAD) • Rapid application development (RAD)

9. Joint Application Development (JAD)- A fact finding technique that brings user into development process as active participants. • 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

10. Joint Application Development • JAD Participants and Roles Figure 3-4

11. Joint Application Development Sys development is a joint effort: Figure 3-5

12. Joint Application Development • JAD Advantages and Disadvantages • More expensive and can be cumbersome (large team) • 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.

13. Rapid Application Development (RAD) • Is a team-based technique that speeds up information systems development and produces a functioning information system • Relies heavily on prototyping and user involvement (allow user to exam a model at early developing stage) • Project team uses CASE tools to build the prototypes and create a continuous stream of documentation

14. Rapid Application Development • RAD Phases (4) and Activities Requirements planning, User design, Construction, Cutover Figure 3-7

15. Rapid Application Development • RAD Objectives • To cut development time and expense by involving the users in every phase of systems development (reduce cost of change) • Successful RAD team must have IT resources, skills, and management support

16. 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 (meet short term purpose, scarifies long term goals) • Might allow less time to develop quality, consistency, and design standards

17. Modeling Tools and Techniques • CASE Tools: Popkin’s eg. :business enterprise model, a business process model,an organization model, a location model, an application model, a data model and a technology model. Figure 3-8

18. Modeling Tools and Techniques • Functional Decomposition Diagrams(FDD) • A top-down representation of business functions and processes, also called structure charts • Start at the top and work way down. During requirement modeling, FDD is used to model business functions and show how they are organized into low-level process. Those processes are used as logical symbols and can be translated into program modules during application development

19. Modeling Tools and Techniques • Functional Decomposition Diagrams Figure 3-9

20. Modeling Tools and Techniques • Unified Modeling Language (UML) - uses OOP design concepts • 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

21. Modeling Tools and Techniques • Unified Modeling Language: case diagrams: visually represent the interaction between users and info. sys. Figure 3-10

22. Modeling Tools and Techniques Unified Modeling Language Table documents for F. 3-10 Figure 3-11

23. Modeling Tools and Techniques Unified Modeling Language Sequence Diagrams: shows timing transactions between objects. Sequence Diagram Figure 3-13, vertical timeline of a successful credit card validation

24. System Requirements Checklist • During requirement modeling, must describe all sys. requirements, which serve as benchmarks to measure the overall acceptability of finished sys. • Five general categories • Outputs • Inputs • Processes • Performance • Controls

25. System Requirements Checklistexamples of Outputs: • A purchasing sys must provide suppliers with up-to date specifications. • An inventory sys. Must produce a daily report showing part no. quantity on hand, quantity available and unit cost • A contact management sys. Must generate a daily reminder list for all sales reps.

26. System Requirements Checklistexamples of Inputs • Input patient services into billing sys. in a hospital • Teachers must enter grades online • Mgr must enter overtime hour sheet for payroll sys.

27. System Requirements Checklistexamples of Processes • Student records sys. must allow access by entering ID or name • Human resources must interface with payroll sys. • Bank must reject over-limit loans

28. System Requirements Checklistexamples of Performance • Online retailer must be operational 24 hours, 7 days • Response time to user should be relatively short • Online inventory sys must flag low-stock items.

29. System Requirements Checklistexamples of Controls • Provide logon security limit access • File access control • Order approval by mgr

30. Future Growth, Costs, and Benefits • Scalability: a system’s ability to handle increased business volume and transactions in the future • 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. eg 1: to ensure an online hotel reservation sys. to work for years of operation, you should forecast the frequency of online queries and estimate turnaround and response time. eg 2: You need to exam current data storage to predict future needs for upgrading current sys. configuration or HW

31. Future Growth, Costs, and Benefits • Total Cost of Ownership • In addition to direct costs, systems developers must identify and document indirect expenses (user support, downtime productivity losses) that contribute to the total cost of ownership (TCO) • Microsoft has developed a method for measuring total costs and benefits, called Rapid Economic Justification (REJ), F. 3-14, p. 103

32. Specific Fact-Finding processes: • Overview • Although software can help you to gather and analyze facts, no program actually performs fact-finding for you • Fact-finding techniques: interviews, document review, observation, surveys, questionnaires, sampling and research • The first step is to identify the information you need, ie. start with a fact-finding plan involving types of who, what, where, when, why and how questions

33. Fact-Finding • Who, What, Where, When, How, and Why? Figure 3-15

34. Fact-Finding • The Zachman Framework (1980s) for enterprise architecture • A model that asks the traditional fact-finding questions in a systems development context

35. Fact-Finding see eg. on p. 105 or refer to government.popkin.com/frameworks/ zachman.htm Figure 3-16

36. Interviews • Systems analysts spend a great deal of time talking with people • Much of that time is spent conducting interviews • Consists of 7 steps

37. 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

38. 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

39. 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

40. Interviews Memo eg. p. 108 Figure 3-18

41. Interviews Figure 3-19

42. 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

43. 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

44. 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 (deliberate info hiding due to poetical job loss, eliminate positions)

45. Other Fact-Finding Techniques • Document Review Fax, hard copies • 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: productivity improved when workers being observed.

46. 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 Sample questionnaires on p. 113, Fig. 3-21

47. 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

48. 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

49. Other Fact-Finding Techniques • Sampling: collect examples of documents Fact: list of 100 complains errors in statement • Systematic sample (select every 20th customer for review) • Stratified sample (select 5 from each of the 4 different zip code areas) • Random sample (select any 20 customers) • Main objective of a sample is to ensure that it represents the overall population accurately

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