SYSE.Preface:3 - Use and System concepts stay linked

A concept of use says how actual or intended Systems participate in an operating situation and what effects are expected. A System concept says what engineered System arrangement could participate that way. Either can expose a defect in the other. SYSE.2 therefore guides an Agent in developing linked use-concept and System-concept candidate families rather than letting one preferred technical solution determine the use story after the fact.

Functional organization and constructive organization answer different questions. A function claim concerns a contribution under conditions. A bearer claim concerns an actual System or intended System referent that could make that contribution. SYSE.5 guides the Agent in developing alternatives for both and making allocation and interface choices explicit. Then use SYSE.6 to compare the candidates for the current engineering use, record the selected result, and state the evidence and conditions that would reopen the choice.