Requirements traceability has been defined by Gotel et al, as "the ability to follow the life of a requirement in both a forward and backward direction". Each traceability link follows a basic life cycle.
The IEEE Standard Glossary of Software Engineering Terminology (IEEE Std 610.12-1990) provides a more general definition of traceability as "the degree to which a relationship can be established between two or more products of the development process, especially products having a predecessor-successor or master-subordinate relationship to one another."
Traceability supports many critical software engineering activities including compliance verification, impact analysis, regression test selection, safety-case construction, requirements allocation, and coverage analysis.
Jarke et al identified four types of traceability that they referred to as (i) backwards from requirements, (ii) forwards to requirements, (iii) backwards to requirements, and (iv) forward from requirements .
1. Olly Gotel, Anthony Finkelstein: Contribution structures (Requirements artifacts). RE 1995: 100-107.
2. Matthias Jarke: Requirements Tracing - Introduction. Commun. ACM 41(12): 32-36 (1998)