For what purpose is a requirements traceability matrix (RTM) primarily used?

A requirements traceability matrix (RTM) is primarily used to perform impact analysis by linking requirements to their corresponding project deliverables and ensuring that all requirements are accounted for throughout the project lifecycle. The RTM provides a clear mapping of each requirement to its origin (such as business needs or stakeholder requests) and its related design, development, and testing elements. This traceability helps project managers and teams assess the impact of changes to any requirement, identify gaps in requirements coverage, and ensure that all requirements lead to appropriate deliverables and test cases.

In the context of project management, understanding requirements and establishing a budget are essential activities but are not the primary purposes of the RTM. While the RTM can assist in understanding requirements more intuitively by clearly mapping them, its main function is related to tracing and verifying that the requirements will be satisfied through the project's outputs. Similarly, while the RTM may indirectly support the creation of test results by ensuring that all requirements have corresponding test cases, this is more of a secondary function rather than the primary purpose of an RTM. Thus, impact analysis is the most direct and critical use of a requirements traceability matrix.