D0178B requirements TRACEABILITY pertains to the correlation of individual requirements to the DESIGN, code, and test elements affiliated with implementing and verifying each REQUIREMENT. Requirements traceability can be many-to-one, and one-to-many. Requirements traceability needs to be from top-to-bottom (requirements to design to code, and requirements to test). This PROVES that all requirements have corresponding design elements, sourcecode, and tests. Requirements traceability also needs to be bottom-to-up (tests to requirements, code to design, and design to requirements). This proves that all code, design, and test elements are NECESSARY and have requirements which they implement or verify.

D0178B requirements traceability pertains to the correlation of individual requirements to the design, code, and test elements affiliated with implementing and verifying each requirement. Requirements traceability can be many-to-one, and one-to-many. Requirements traceability needs to be from top-to-bottom (requirements to design to code, and requirements to test). This proves that all requirements have corresponding design elements, sourcecode, and tests. Requirements traceability also needs to be bottom-to-up (tests to requirements, code to design, and design to requirements). This proves that all code, design, and test elements are necessary and have requirements which they implement or verify.