1. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Requirements Traceability 1.4.2001 Virve Leino QURE Project Software Business and Engineering Institute Helsinki University of Technology

2. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Contents Definition of requirements traceability Benefits of requirements traceability Factors affecting the need for traceability Traceability classes and relation types Techniques to document traceability Tools to document traceability Tasks to implement traceability Lessons learned in QURE -project

3. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Requirements traceability A requirement is traceable if you can discover: who suggested the requirement, why the requirement exists, what requirements are related to it and how it relates to other information such as systems design, implementation and documentation.

4. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Benefits of Requirements Traceability Traceability helps in: Requirements change management Validation and reuse of requirements Understanding how and why the system meets the needs of the stakeholders

5. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Factors affecting the need for traceability Type of the system Estimated system lifetime Number of requirements Size of the project team Level of organizational maturity Specific customer requirements

6. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Traceability classes 1/2 Pre- and post-traceability Origins of requirements Requirements System process artifacts Pre-traceabilityPost-traceability

7. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Traceability classes 2/2 Forward and backward traceability Origins of requirements Requirements System process artifacts Forward traceability Backward traceability

8. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Traceability relation types 1) requirement-source 4) requirement-requirement 2) requirement-rationale 5) requirement-component 3) requirement-people 6) requirement-verification Rationales Sources like: companies standards Requirements Components Verification cases :-) People 1 2 3 4 5 6

9. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Techniques to Document Traceability Information 1/3 1. Identifiers 2. Attributes 3. List 4. Table example of each technique follow...

10. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Techniques to document 2/3 1. Requirement-requirement information documented using requirements’ identifiers: 2. Requirement-source and requirement-verification documented using requirements’ attributes:

11. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Techniques to document 3/3 3. Requirement-component information documented using list: 4. Requirement-component information documented using table:

12. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Tools to Document Traceability Information General purpose tools (eg. spreadsheet programs, word processors, hypertext editors) suitable for small and short term projects not sufficient for extensive requirements tracing purposes Requirements management tools suitable for projects producing large and complex systems require investments (eg. licences, training end-users, system maintenance, consultation)

13. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Tasks to Implement Traceability Analyze the company’s need for traceability Define which traceability relations should be documented Select techniques and tools to be used Choose when, by whom and to where information should be documented Ensure that practices are taken into use

14. SoberIT Software Business and Engineering Institute HELSINKI UNIVERSITY OF TECHNOLOGY Lessons Learned in QURE -project Pre-traceability: first traceability that companies could benefit from easy to document (compared post- traceability) tool support is not needed Post-traceability: many prerequisites: clearly stated requirements, components and verificatíon-cases tool support is often needed to document it