In this paped, we investigate and discuss the underlying nature ofthe requirements tmceabirity problem. Our work is based on empirical studies, involving aver IO0 pmctitioners, and an evaluation of current support. We introduce the distinction beiween pre-requirements specification @re-Rs) tmceability and post-requirements specijication @st-RS) tmceability, to demonstrate why an all-encompassing solution to the problem is unlikely, and to provide a fmmework through which to understand its mulhijhceted nature. We report how the majority of the problems attributed to poor requirements tmceability are due to inadequate pre-RS traceability and show the fundamental need for improvements here. In the remainder of the paper, we present an analysis of the main baniers confronting such improvements in practice, identifi relevant areas in which advances have been (or can be) made, and make recommendations for research. [Keywords: requirements traceability, pre-requirements specification traceability, post-requirements specification traceability, requirements engineering practice, requirements traceability tools.] Requirements traceability (RT) is recognised as a concern in an increasing number of standards and guidelines for requirements engineering (RE) [ 121. This concern is reflected by the various systems that have been developed and a growing research interest in the area [25]. Despite many advances, RT remains a widely reported problem area by industry. We attribute this to inadequate problem analysis. Definitions of "requirements traceability" are discussed in detail later, though we provide the following for orientation: Requirements traceability refers to the ability to describe and follow the life of a requirement, in both a forwards and backwards direction. 0 Pre-RS traceability refers to those aspects of a requirement's life prior to inclusion in the RS. 0 Post-RS traceability refers to those aspects of a requirement's life that result from inclusion in the RS. In this paper, we analyse the RT problem in detail. We describe our empirical investigations in Section 2, review the current support in Section 3, examine the underlying causes of the problem in Section 4, and present a framework for addressing these in Section 5. Section 6 lists the main problems '123) is a longer version of this paper. The empirical work and surveys we refer to are hlly documented as a BT/Oxford University research report. 0-8186-5480-5/94 $03.00 0 1994 IEEE facing pre-RS traceability improvements, Section 7 identifies how some of these can be tackled, and Section 8 discusses that aspect of the composite problem which is the subject of our ongoing research agenda at Imperial College. Numerous data gathering techniques were used to define and analyse the RT problem. The empirical exercises took place over 1 year and involved more than 100 practitioners. Their work areas covered all aspects of development, maintenance and management, their experience ranged from 9 months to 30 years; and the projects they were involved with varied in number, type, and size. A detailed specification for RT support was produced in parallel. Here, introspection helped to identify requirements to support both this activity and its traceability. The literature was surveyed, and over 100 commercial tools and research products were reviewed, to gather viewpoints regarding: what RT is; why it is needed; what problems it involves, and to locate relevant research and development. 5 semi-structured sessions were conducted. These involved 37 practitioners spread across 5 sites of a U.K. company. Each session lasted 1 hour, was audio taped, and transcribed. The data were used to: consolidate the above, discover how RT problems are overcome (if at all); get suggestions for improvements; and to inform questionnaire design. A 2-stage questionnaire was used. Stage 1 was designed to rapidly gather data from a wide population of practitioners and to target those from whom more detail could be gathered. 80 were distributed and 69% returned. Stage 2 was tailored to the primary working areas and experiences of individual practitioners, using a reusable pool of questions. 39 were distributed and 85% returned. These provided a deeper understanding of the problems and preliminary requirements to address them. 2 informal interview sessions were subsequently conducted with the respondents. Each lasted 1.5 hours and were used to corroborate their answers, appraise their validity, extract additional information, and to check preliminary analysis. Data were also gathered following the observation of, and some participation in, a variety of RE exercises. For instance, Rapid Application Development workshops were observed,
Consequently, the importance of rationalising requirements has motivated the need for managing requirements traceability: the ability to describe and follow the life of a requirement, in both a forward and backwards direction REF .
An analysis of the requirements traceability problem
Proceedings of IEEE International Conference on Requirements Engineering
Proceedings of IEEE International Conference on Requirements Engineering
Engineering Computer Science