SAD 1st PPT
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This chapter discusses the systems analysis phase of the SDLC. The objectives are to understand the proposed project, ensure it supports business needs, and provide a foundation for design. Key activities include requirements modeling using tools like use case diagrams, data and process modeling, and considering development strategies. The chapter also covers fact-finding techniques like interviews, documentation review and questionnaires to understand requirements and system stakeholders.
SAD 1st PPT
- 1. Systems Analysis & Design 7th Edition Chapter 3 1
- 2. Phase Description Systems analysis is the second of five phases in the systems development life cycle (SDLC) Uses requirements modeling and data and process modeling to represent the new system Before proceeding to the next phase, systems design, you will consider system development strategies 2
- 3. Chapter Objectives Describe systems analysis phase activities and the end product of the systems analysis phase Explain joint application development (JAD) and rapid application development (RAD) Understand 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 4
- 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 5
- 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 6
- 7. Systems Analysis Phase Overview The overall objective is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for system development You use a models and other documentation tools to visualize and describe the proposed system 7
- 8. Systems Analysis Phase Overview Systems Analysis Activities – Requirements modeling • • • • • Outputs Inputs Processes Performance Security 8
- 9. Systems Analysis Phase Overview Systems Analysis Activities – Data and process modeling – Development Strategies • System requirements document 9
- 10. Systems Analysis Phase Overview Systems Analysis Skills – Analytical skills – Interpersonal skills Team-Oriented Methods and Techniques – Joint application development (JAD) – Rapid application development (RAD) 10
- 11. 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 – One popular strategy for user involvement is a JAD team approach 11
- 12. Joint Application Development JAD Participants and Roles – JAD participants should be insulated from the distraction of day-to-day operations – Objective is to analyze the existing system, obtain user input and expectations, and document user requirements for the new system 12
- 13. Joint Application Development JAD Advantages and Disadvantages – Advantages • 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 – Disadvantages • More expensive and can be cumbersome if the group is too large relative to the size of the project 13
- 14. 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 Process continues until the system is completely developed and users are satisfied 14
- 15. Rapid Application Development • RAD Phases and Activities 15
- 16. 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
- 17. Rapid Application Development RAD Advantages and Disadvantages – Advantages • Systems can be developed more quickly with significant cost savings – Disadvantages • 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
- 18. Modeling Tools and Techniques CASE Tools Functional Decomposition Diagrams – Also called structure charts 18
- 19. Modeling Tools and Techniques • Data Flow Diagrams 19
- 20. Modeling Tools and Techniques Unified Modeling Language – Widely used method of visualizing and documenting software systems design – Use case diagrams • Actor – Sequence diagrams 20
- 21. System Requirements Checklist System requirement Five general categories – Outputs – Inputs – Processes – Performance – Controls 21
- 22. System Requirements Checklist Outputs – The Web site must report online volume statistics every four hours, and hourly during peak periods – The inventory system must produce a daily report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all sorted by part number 22
- 23. System Requirements Checklist Inputs – Manufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiency – The department head must enter overtime hours on a separate screen 23
- 24. System Requirements Checklist Processes – The student records system must calculate the GPA at the end of each semester – As the final step in year-end processing, the payroll system must update employee salaries, bonuses, and benefits and produce tax data required by the IRS 24
- 25. System Requirements Checklist Performance – The system must support 25 users online simultaneously – Response time must not exceed four seconds 25
- 26. System Requirements Checklist Controls – The system must provide log-on security at the operating system level and at the application level – An employee record must be added, changed, or deleted only by a member of the human resources department 26
- 27. 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 27
- 28. Future Growth, Costs, and Benefits Total Cost of Ownership – Total cost of ownership (TCO) is especially important if the development team is evaluating several alternatives – One problem is that cost estimates tend to understate indirect costs – Rapid Economic Justification (REJ) 28
- 29. Fact-Finding Fact-Finding Overview – The first step is to identify the information you need – Develop a fact-finding plan Who, What, Where, When, How, and Why? – Difference between asking what is being done and what could or should be done 29
- 30. Fact-Finding The Zachman Framework – Zachman Framework for Enterprise Architecture – Helps managers and users understand the model and assures that overall business goals translate into successful IT projects 30
- 31. Interviews Systems analysts spend a great deal of time talking with people Much of that time is spent conducting interviews 31
- 32. Interview Step 1: Determine the People to Interview – Informal structures Step 2: Establish Objectives for the Interview – Determine the general areas to be discussed – List the facts you want to gather 32
- 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 33
- 34. Interviews Step 4: Prepare for the Interview – Careful preparation is essential because interview is 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 34
- 35. Interviews Step 5: Conduct the Interview – Develop a specific plan for the meeting – Begin by introducing yourself, describing the project, and explaining interview objectives – Use engaged listening – Allow the person enough time to think about the question – After interview, summarize the session and seek a confirmation 35
- 36. Interviews Step 6: Document 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 36
- 37. 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 37
- 38. 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 your observations in advance – Hawthorne Effect 38
- 39. Other Fact-Finding Techniques Questionnaires and Surveys – When designing a questionnaire, the most important rule of all is to make sure that your questions collect the right data in a form that you can use to further your fact-finding – Fill-in form 39
- 40. 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 40
- 41. Other Fact-Finding Techniques Research – Can include the Internet, IT magazines, and books to obtain background information, technical material, and news about industry trends and developments – Site visit 41
- 42. Other Fact-Finding Techniques Interviews versus Questionnaires – Interview is more familiar and personal – Questionnaire gives many people the opportunity to provide input and suggestions – Brainstorming – Structured brainstorming – Unstructured brainstorming 42
- 43. 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 so related material is located easily 43
- 44. Documentation Software Tools – CASE Tools – Productivity Software • Word processing, spreadsheets, database management, presentation graphics programs • Histogram 44
- 45. Documentation Software Tools – Graphics modeling software – Personal information managers • Personal information manager (PIM) • Handheld computers • Personal digital assistants (PDAs) – Wireless communication devices 45
- 46. Preview of Data and Process 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 46
- 47. Chapter Summary The systems analysis phase includes three activities: requirements modeling, data and process modeling, and consideration of development strategies The main objective is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for the systems design phase 47
- 48. Chapter Summary The fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and research 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 48