Glossary · Evidence, assurance and traceability
Trace link
Also known as: traceability link
In systems engineering, a trace link is an explicit, typed relationship between two lifecycle items, such as a requirement and its verification evidence. The type states what the link means, for example “verified by”, “mitigated by” or “derived from”.
- Systems engineering
- Data and interfaces
In one sentence
A trace link is an explicit, typed relationship between two lifecycle items, the smallest unit of traceability.
Example
In the requirements tool of a robot cell project, the hazard “crushing at the gripper” has a “mitigated by” trace link to the safety function “safe speed in collaborative mode”, which has a “verified by” link to test report TR-112.
How it applies
- Evidence: Typed links make queries meaningful: "show all hazards without a verified mitigation" only works if "mitigated by" and "verified by" are distinct types.
- Data and interfaces: Links between tools need stable IDs on both ends. Links to file paths or document titles break when files move.
- Change control: Trace links drive impact analysis. When an item changes, follow its links to find what must be reviewed.
- Semantic web: A typed link is a triple: subject, predicate, object. RDF and linked data offer a standard way to express trace links across tools.
In RDF
@prefix ex: <https://example.com/trace#> .
ex:HAZ-014 ex:mitigatedBy ex:SF-03 .
ex:SF-03 ex:verifiedBy ex:TR-112 .
Trace link vs. reference
A plain reference ("see document X") says that two items are related. A trace link says how, and can be checked and queried.