Requirements Tracing is defined as the ability to describe and follow the life of a requirement, in both a forward and backward direction, ideally through the whole systems life cycle. Requirements tracing should capture all levels of requirement engineering. These levels can be defined as the technical, cognitive, and social levels. The technical level can be described as taking the customer’s interests and needs and applying them to the product’s goals, constraints, and outcomes. The cognitive level is developing an understanding between the customer and the supplier on the functionality, non-functionality, and possible side effects of the technical level. Finally, the social level is documenting the technical and cognitive levels in a comprehensive manger.

Requirement traceability is important to the project in many ways.  The CMM covers requirement traceability primarily in Software Configuration Management, but activity 10 of Software Product Engineering states the specific need for consistency and traceability between software work products.  The Requirement Management KPA states the need to manage requirements so they can be easily mapped to a specified requirement in the later steps of the software development life-cycle.  ISO also requires the ability to trace each requirement from the beginning to the end of the development phases.