The purpose of Trace Requirements is to ensure that requirements and designs at different levels are aligned to one another, and to manage the effects of change to one level on related requirements.
Requirements traceability identifies and documents the lineage of each requirement, including its backward traceability, its forward traceability, and its relationship to other requirements. Traceability is used to help ensure that the solution conforms to requirements and to assist in scope, change, risk, time, cost, and communication management. It is also used to detect missing functionality or to identify if there is implemented functionality that is not supported by any requirement.
Traceability enables:
◦ faster and simpler impact analysis,
◦ more reliable discovery of inconsistencies and gaps in requirements,
◦ deeper insights into the scope and complexity of a change, and
◦ reliable assessment of which requirements have been addressed and which
have not.
It is often difficult to accurately represent needs and solutions without taking into account the relationships that exist between them. While traceability is valuable, the business analyst balances the number of relationship types with the benefit gained by representing them. Traceability also supports both requirements allocation and release planning by providing a direct line of sight from requirement to expressed need.
The following images show examples of visual representations of traceability for a process and for software requirements
Level of Formality Consider the value, nature, and use of each link. The tracing effort increases significantly when the number of requirements or level of formality rises.
Relationships The business analyst contemplates several types of relationships when defining the traceability approach: Derive, Depends, Satisfy, and Validate.
Traceability Repository The requirements traceability is documented and maintained following the methods identified by the business analysis approach.