Requirements Verification & Validation

1. Requirements Engineering & Project Management Lecture 9 Requirements Verification & Validation Jerzy.Nawrocki@put.poznan.pl www.cs.put.poznan.pl/jnawrocki/require/

2. XPrince Roles and V&V Architect Analyst Project Manager + Auditor Time Time J.Nawrocki, Verification and Validation

3. XPrince Artefacts and V&V Architect Analyst Aim & Scope Business Model and System Scope A&S Plan Most Important Use Cases Architect. Vision & Tools Init. Project Plan Architecture Requirements Spec. Initial Prototype (code + test cases) Architect. Plan Mockup Accept. Tests Frame GUI Design Updat. Proj. Plan Project Manager J.Nawrocki, Verification and Validation

4. Agenda • Requirements Analysis & Negotiation • Requirements Validation • Capture & Recapture • Introduction • XPrince Team • Project Lifecycle • The Analyst Role • The Architect Role • The Project Manager Role • Scaling up • Conclusions J.Nawrocki, Verification and Validation

5. Agenda • Requirements Analysis & Negotiation • Requirements Validation • Capture & Recapture • Introduction • XPrince Team • Project Lifecycle • The Analyst Role • The Architect Role • The Project Manager Role • Scaling up • Conclusions J.Nawrocki, Verification and Validation

6. Requirements Analysis and Negotiation Basic Interm Adv 36 21 9 8 - - 6 6 1 5 2 1 4 1 - 3 3 - 4 3 1 4 3 2 2 3 4 The requirements document Requirements elicitation Reqs analysis & negotiation Describing requirements System modelling Requirements validation Requirements management RE for critical systems J.Nawrocki, Verification and Validation

7. Basic guidelines Analysis and negotiation Person 1 Institution System Person 2 Device • Define system boundaries • Process requirements • System requirements • Software requirements J.Nawrocki, Verification and Validation

8. Basic guidelines Analysis and negotiation • Define system boundaries • Use checklists for requirements analysis J.Nawrocki, Verification and Validation

9. A Checklist Example Analysing system’s boundaries • Does a requirement imply the need for some decision-making based on incomplete or unreliable information? • Will the implementation of a requirement need information which is outside the defined database for the system? • Is a requirement concerned with the core functionality of the system? • Is a requirement concerned with the functionality or performance of equipment which is external to the system? J.Nawrocki, Verification and Validation

10. Another Checklist Example IEEE Std 830-1998 a) Correct; b) Unambiguous; c) Complete; d) Consistent; e) Ranked for importance and/or stability; f) Verifiable; g) Modifiable; h) Traceable. J.Nawrocki, Verification and Validation

11. A Checklist for Use Cases Is there a shared clear vision? Are there visible boundaries? Is there clear cast of characters describing end-users? Are all user-level use-cases user-valued transactions? Does each use case have a complete single goal? Is its naming clear and depicting the goal? Are the alternatives an exhaustive set? Are use cases describing just behaviour? Are adornments properly used? Are the conditions detectable? J.Nawrocki, Verification and Validation

12. Basic guidelines Analysis and negotiation • Define system boundaries • Use checklists for requirements analysis Provide software to support negotiations Plan for conflicts and conflict resolution Prioritise requirements J.Nawrocki, Verification and Validation

13. Intermediate guidelines Analysis and negotiation • Classify requirements using a multidimensional approach System, User interface, Database, Communications, Security J.Nawrocki, Verification and Validation

14. Intermediate guidelines Analysis and negotiation • Classify requirements using a multidimensional approach System, User interface, Database, Communications, Security Use interaction matrices to find conflicts and overlaps J.Nawrocki, Verification and Validation

15. Advanced guidelines Analysis and negotiation • Assess requirements risks J.Nawrocki, Verification and Validation

16. Agenda • Requirements Analysis & Negotiation • Requirements Validation • Capture & Recapture • Introduction • XPrince Team • Project Lifecycle • The Analyst Role • The Architect Role • The Project Manager Role • Scaling up • Conclusions J.Nawrocki, Verification and Validation

17. Requirements Validation Basic Interm Adv 36 21 9 8 - - 6 6 1 5 2 1 4 1 - 3 3 - 4 3 1 4 3 2 2 3 4 The requirements document Requirements elicitation Reqs analysis & negotiation Describing requirements System modelling Requirements validation Requirements management RE for critical systems J.Nawrocki, Verification and Validation

18. Basic guidelines Requirements validation • Check that the requirements document meets your standard • Organise formal requirements inspections  J.Nawrocki, Verification and Validation

19. Reviews and Inspection Review Artefact • Review = Analysis of an artefact (e.g. code, document) done by 1 or more people. • Goals of review: • Quality assurance • Knowledge dissemination J.Nawrocki, Verification and Validation

20. FTR Procedure Casting • Producer (author) • Project Manager • Facilitator • Reviewer(s) • Recorder FTR = Formal Technical Review (Formalny przegląd techniczny) J.Nawrocki, Verification and Validation

21. FTR Procedure • 1. Producer advices the Project Manager + Facilitator that the artefact is ready and sends them a copy. • 2. Facilitator contacts all the inspection participants and decides about the date and time of the meeting (the sooner the better). He also sends the artefact to the reviewers. 3. Facilitator writes the agenda for the meeting. 4. FTR meeting 5. Recorder prepares inspection report and sends it to the participants. A copy of it goes also to the Project Manager. J.Nawrocki, Verification and Validation

22. FTR Meeting Agenda’s template (I) • Facilitator: Presents the agenda. The participants may propose changes. • Recorder: Collects copies of the preparation forms. • Producer: Presents the artefact. Reviewers may ask questions. Recorder takes notes (issues and defects). J.Nawrocki, Verification and Validation

23. FTR Meeting Agenda’s template (II) • Recorder: Summerizes the issues and defects. • All participants except the producer: Initial secret vote. • Recorder: Collects the votes and presents the result. • Producer: “Last word” • All the participants except the producer: Final secret vote. J.Nawrocki, Verification and Validation

24. FTR Meeting Decision • Acceptance. No modifications are necessary. • Conditional acceptance. There are some defects but additional inspection is not necessary (the Project Manager will check the final version). • Rejection. There are serious defects and an additional inspection is necessary. J.Nawrocki, Verification and Validation

25. Agenda • Requirements Analysis & Negotiation • Requirements Validation • Capture & Recapture • Introduction • XPrince Team • Project Lifecycle • The Analyst Role • The Architect Role • The Project Manager Role • Scaling up • Conclusions J.Nawrocki, Verification and Validation

26. Capture-Recapture How many fish are there? J.Nawrocki, Verification and Validation

27. Capture-Recapture 1 Catch a sample J.Nawrocki, Verification and Validation

28. Capture-Recapture 1 Catch a sample 2 Tag them J.Nawrocki, Verification and Validation

29. Capture-Recapture 1 Catch a sample 2 Tag them 3 Release them J.Nawrocki, Verification and Validation

30. Capture-Recapture 1 Catch a sample 2 Tag them 3 Release them 4 Catch another group J.Nawrocki, Verification and Validation

31. Capture-Recapture 1 Catch a sample 2 Tag them 3 Release them 4 Catch another group 5 How many tagged? J.Nawrocki, Verification and Validation

32. Capture-Recapture 1 Catch a sample 2 Tag them 3 Release them 4 Catch another group 5 How many tagged? 20 30 5 J.Nawrocki, Verification and Validation

33. Capture-Recapture Total = 20 * 30 / 5 = 120 1 Catch a sample 2 Tag them 3 Release them 4 Catch another group 5 How many tagged? 20 30 5 J.Nawrocki, Verification and Validation

34. Capture-Recapture B A Artefact C Total defects = A * B / C If C = 0 ... J.Nawrocki, Verification and Validation

35. Capture-Recapture A B More than 2 reviewers Most unique defects found All others Total defects = A * B / C J.Nawrocki, Verification and Validation

36. Basic guidelines Requirements validation • Check that the requirements document meets your standard • Organise formal requirements inspections  Use multidisciplinary teams to review requirements Define validation checklists J.Nawrocki, Verification and Validation

37. Intermediate guidelines Requirements validation • Use prototyping to animate requirements • Write a draft user manual • Propose requirements test cases  J.Nawrocki, Verification and Validation

38. Advanced guidelines Requirements validation • Paraphrase system models  J.Nawrocki, Verification and Validation

39. Questions? ? J.Nawrocki, Verification and Validation

40. Quality assessment • 1. What is your general impression? (1 - 6) • 2. Was it too slow or too fast? • 3. What important did you learn during the lecture? • 4. What to improve and how? J.Nawrocki, Verification and Validation