Lecture 4

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Lecture 4

  1. 1. Determining System Requirements
  2. 2. SDLC Project Identification & Selection Project Initiation & Planning Analysis ** Logical Design Physical Design Implementation Maintenance
  3. 3. Requirements Determination  System requirements  Functional requirements  Current and future functions  Current and future data  Current and future employee jobs
  4. 4. Requirements Structuring  Two essential views of the current and replacement information systems. Both are describing the same system, but in a different way.  Process view: The sequence of data movement & handling operations within the system  Data flow diagrams  Data: The inherent structure of data independent of how or when it is processed  Entity-relation diagrams
  5. 5. Remember to...
  6. 6. Who will you get info from?  User Stakeholders  Users  Managers  Client Stakeholders  Technical Stakeholders
  7. 7. What Information Do You Need?  1.  2.  3.
  8. 8. Traditional Methods for Determining System Requirements  Administering questionnaires  Interviewing and listening  Interviewing groups  Directly observing users  Analyzing procedures & other documents
  9. 9. Administering Questionnaires Advantages & Disadvantages  Strengths  1.  2.  3.  Weaknesses  1.  2.  3.
  10. 10. Give Me Ambiguity or Give Me Something Else!  How often do you back up your computer files?  A. Frequently  B. Sometimes  C. Hardly at all  D. Never
  11. 11. This is better…  How often do you back up the computer files stored on the hard disk on the PC you use for over 50% of your work time?  A. Frequently (at least once per week)  B. Sometimes (from 1 to 3 times per month)  C. Hardly at all (once per month or less)  D. Never
  12. 12. Interviewing & Listening  Before  During the interview  Afterwards
  13. 13. During the Interview  Beginning  Introduction, open-ended questions, interest & attention  Middle  Open & close-ended questions, f-u questions, active listening, provide feedback, limit note-taking  End  Summarize, request feedback and/or f-u, ask for corrections
  14. 14. Interviews Advantages & Disadvantages  Strengths  Extracts both qualitative and quantitative data  Detailed and summary data  Good way to find needs and assumptions  Weaknesses  Requires skills  May be biased; May collect lots of useless data  Expensive, time consuming  Requires other methods to verify results
  15. 15. How do you choose interview questions?  Open-ended questions  1.  2.  3.  Closed-ended questions  1.  2.  3.
  16. 16. Find out about someone’s job  Write 3 open-ended questions  Ask 3 open-ended questions (You may substitute questions during interview.)  Write down answers  Write 3 closed-ended questions  Ask 3 closed-ended questions (You may substitute questions during interview.)  Write down answers
  17. 17. Interviewing Groups Adv & Disadv  Strengths  Not biased by one user’s opinion  Can get many user’s opinion  Weaknesses  With many people present, decision- making takes time  Interruptions during process
  18. 18. You May Need to Analyze Work Procedures  Work procedures describe a particular job or task  May show duplication of effort  May find missing steps  May contradict info collected from interviews, questionnaires, and observations  Formal systems vs informal systems
  19. 19. Directly Observing Users  Strengths  Doesn’t rely on a user’s memory  More objective and accurate than interviews  Weaknesses  Hawthorne effect  Time consuming
  20. 20. Temporary Job Assignment  Strengths  Good for learning context, terminology, procedures  Provides insight for other questions  Get operation “feel”; adds to analysts credibility with users  Weaknesses  Time Consuming  May bias future work design towards way things are currently done
  21. 21. Reviewing internal documents  Strengths  Good way to learn history and politics  Explains current context  May help understand why and way of current procedures & applications  Weaknesses  May bias future work design  Not useful for obtaining current attitudes or motives
  22. 22. Modern Methods for Determining System Requirements  Prototyping  Joint Application Design (JAD) - Intensive meetings between users, managers, sponsor, & systems analysts to discuss & review system requirements  Group Support Systems (GSS) to share ideas & voice opinions  BPR – Business process reengineering  CASE tools to analyze existing systems

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