SYSE.26:4.1 - Begin with the user’s completed undertaking

Walk through an actual or explicitly constructed attempt with a representative user. Ask what they will do with the result: compare a model, test a change, release a configuration, or accept a manufactured item. Work backwards from that use to the smallest sufficient input and returned result.

Keep the user’s result separate from intermediate provider activity. An accepted request, a booked slot, a running job and an inspected item are different results. A booking may be sufficient when the user is scheduling; it is insufficient when they are deciding whether a component passed a test.

Name the System or provider that supplies each indispensable operation. Recover existing configuration identities and conditions through SYSE.13. When a professional Method is missing, name its required result and supplier. A clear description of a missing operation is useful for design, but does not justify promising that operation to users.