Post-requirements traceability. Not only the requirements themselves should be traced but also the requirements relationship with all the artifacts associated with it, such as models, analysis results, test cases, test procedures, test results and documentation of all kinds. Even people and user groups associated with requirements should be traceable. Requirements are realized into design artifacts, implementation, and finally, verified. Artifacts tied to the latter stages should be traced back to the requirements as well. This is typically done via a requirements traceability matrix.