1. Requirements Modeling
Chapter 3
Requirements Modeling

2. Phase Description
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, you will consider system development strategies

3. Chapter Objectives
Describe systems analysis phase activities and the end product of the systems analysis phase
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 explain use case diagrams and sequence diagrams 3

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 3

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 then discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research 4

7. 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

8. Systems Analysis Phase Overview
Systems Analysis Skills
Analytical skills
Interpersonal skills
Team-Oriented Methods and Techniques
Joint application development (JAD)
Rapid application development (RAD)

9. 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

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

11. Joint Application Development
Figure 3-5

12. 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.

13. 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

14. Rapid Application Development
RAD Phases and Activities
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
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

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
Might allow less time to develop quality, consistency, and design standards

17. Modeling Tools and Techniques
CASE Tools
Figure 3-8

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

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

20. 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

21. Modeling Tools and Techniques
Unified Modeling Language
Figure 3-10

22. Modeling Tools and Techniques
Unified Modeling Language
Figure 3-11

23. Modeling Tools and Techniques
Unified Modeling Language
Sequence Diagram
Figure 3-13

24. System Requirements Checklist
Five general categories
Outputs
Inputs
Processes
Performance
Controls

25. 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

26. 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)
Microsoft has developed a method for measuring total costs and benefits, called Rapid Economic Justification (REJ)

27. 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

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

29. Fact-Finding The Zachman Framework
A model that asks the traditional fact-finding questions in a systems development context

30. Fact-Finding
Figure 3-16

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

32. 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

33. 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

34. 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

35. Interviews
Figure 3-18

36. Interviews
Figure 3-19

37. 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

38. 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

39. 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

40. 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

41. 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

42. 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

43. 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

44. Other Fact-Finding Techniques
Sampling
Systematic sample
Stratified sample
Random sample
Main objective of a sample is to ensure that it represents the overall population accurately

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

46. 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

47. 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

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

49. Documentation Software Tools Presentation graphics
Personal information managers

50. 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

51. 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. 49

52. 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 49