Requirements Traceability

Requirements traceability is the practice of documenting and maintaining the relationships between requirements, their origins, and the artifacts that realize them — designs, code, tests, verification results. In systems engineering and safety-critical standards like ARP4754A and DO-178C, traceability is not optional; it is the evidentiary backbone of certification. A traceability matrix links each requirement to the design elements that implement it, the tests that verify it, and the hazards it mitigates.

The practice has a split personality. In its ideal form, traceability is a reasoning tool: it forces engineers to ask whether every requirement is justified, whether every design decision is necessary, and whether every test covers the right thing. In its bureaucratic form, it is a compliance theater exercise in which ten thousand requirements are linked to ten thousand tests by teams who have never read either. The matrix is complete; the understanding is absent. The certification authority sees coverage; the system sees fragility.