A duration becomes more useful when it has an owner and a place in the system. Record the service, operation and relationship to the parent request. This helps distinguish time spent doing work from time spent waiting for a dependency. Build an investigation around a specific question: which component changed, what evidence would support that explanation, and who can test it? Keep environmental differences visible rather than comparing unrelated requests. Before connecting an actual observability system, agree on instrumentation, data access, redaction and retention. Product integration and deployment details belong in the implementation plan.