1. Requirements Identification and Analysis M. M. Pickard Department of Computer Science

2. 2 Preliminary Investigation l Interviews l Observation l Documentation review l Survey l Questionnaire

3. 3 Interview l Determine interviewee(s) l Establish objectives l Prepare (setting, timing, questions) –Appearance is important! l Conduct the interview –Establish rapport (begin w/handshake) –Max length: 45-60 min. l Document the interview l Evaluate

4. 4 Interview Question Types l Open-ended l Closed –Multiple-choice –Bipolar l Probe (follow-up) l Avoid leading questions

5. 5 Interview Record l Note-taking l Tape recording l Combination l Write report ASAP after the interview

6. 6 Observation l Workflow l Time sampling –For example, a number of randomly chosen x- minute intervals during several days. l Event-based

7. 7 Documentation Review l Operating procedures l Forms l Archival data l Background documents –Letters, memos, reports

8. Questionnaire/survey When are they appropriate?

9. 9 Questionnaire/Survey l Use when –subjects are widely dispersed –there are a large number to be polled –conducting an exploratory study –setting the stage for interviews l Questions must be transparently clear l Use open-ended questions sparingly to gather opinions

10. 10 More About Sampling... l Types of Samples –convenience samples –purposive samples –simple random samples –complex random samples l systematic sampling l cluster sampling l stratified sampling

11. 11 Determining Sample Size l Statistical Methods –Sampling on attributes –Sampling on variables

12. 12 Input Considerations l Avoid assumptions. l Sometimes output drives the input. l Besides “normal-mode” processing, don’t forget: – exceptions and unusual cases – interdependencies –error and recovery modes

13. 13 Input Considerations l Identify equivalence classes. l Give special attention to boundary values. l Test case formation can be driven by above factors.

14. 14 Prototyping l Requirements identification/analysis is one place prototyping can be very helpful. l Interface issues can be explored. l Should the prototype be a basis for further development?

15. 15 Requirements Identification Methods l There are different methods for identifying requirements. l The methods used depend on the situation. l Proper identification and documentation of requirements is essential to success. l Test planning begins here!