Lecture 8.pptx
- 1. Systems Analysis and Design Requirements Modeling
- 2. System Requirements Checklist • System requirement • After gathering information about new system, system analyst needs to describe all system requirements. • system requirements: is a characteristics, or features that must be included in an information system to satisfy business requirement and be acceptable to users. • Five general categories: Outputs, Inputs, Processes, Performance, and Controls
- 3. System Requirements Checklist (cont.) • Outputs Examples • 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. 3
- 4. System Requirements Checklist (cont.) • Inputs Examples • 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. 4
- 5. System Requirements Checklist (cont.) • Processes Examples • 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. 5
- 6. System Requirements Checklist (cont.) • Performance Examples • The system must support 25 users online simultaneously • Response time must not exceed four (4) seconds. 6
- 7. System Requirements Checklist (cont.) • Controls Examples • The system must provide logon 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. 7
- 8. Future Growth, Costs, and Benefits • Scalability • Scalability refers to 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, Because it will have a longer useful life. • To evaluate scalability, you need information about projected future volume for all outputs, inputs, and processes. 8
- 9. Future Growth, Costs, and Benefits (cont.) • 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 , such as user support and downtime productivity losses. 9
- 10. Fact-Finding • Fact-Finding Overview • First, you must identify the information you need. • Develop a fact-finding plan. • Who, What, Where, When, How, and Why? • Difference between asking what is being done (current situation) and what could or should be done (future improvement). • Know now first, and future comes later. 10
- 11. Who, What, Where, When, How, and Why? 11
- 12. Fact-Finding (cont.) • 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. 12
- 13. Interviews • interview is a planned meeting during which the analyst obtains information from another person. • Step 1: Determine the People to Interview • Informal structures: some people have more influence or knowledge than appears on an organization chart. • Step 2: Establish Objectives for the Interview • Determine the general areas to be discussed. • List the facts you want to gather 13
- 14. Interviews • Step 3: Develop Interview Questions • Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents. The interview should consist of several different kinds of questions: • Avoid leading questions. • Open-ended questions How is the task performed? • Closed-ended questions: limited and specific responses How many pc do you have in this department? • Range-of-response questions On a scale of 1 to 10, how effective was your training? 14
- 15. Interviews • Step 4: Prepare for the Interview • Careful preparation is essential because an interview is an important meeting. • Limit the interview to no more than one hour. • Send a list of topics • Ask the interviewee to have samples available. 15
- 16. Interviews • Step 5: Conduct the Interview • Develop a specific plan for the meeting. • Begin by introducing yourself, describing the project, and explaining your interview objectives. • Engaged listening. • Allow the person enough time to think about the question. • After an interview, you should summarize the session and seek a confirmation. 16
- 17. Interviews • Step 6: Document the Interview –Note taking should be kept to a minimum. –After conducting the interview, you must record the information quickly –After the interview, send memo to the interviewee expressing your appreciation. –Note date, time, location, purpose of the interview, and the main points you discussed so the interviewee has a written summary and can offer additions or corrections. 17
- 18. 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. 18
- 19. 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 19
- 20. 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: collect data on the Internet or a company intranet. 20
- 21. 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. 21
- 22. 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: the objective is to observe a system in use at another location. 22
- 23. 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 23
- 24. 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. 24
- 25. Documentation • Software Tools • CASE Tools • Productivity Software • Word processing, spreadsheets, database management, presentation graphics, and collaborative software programs • Histogram • Graphics modeling software • Personal information managers. 25