Use-Case Brief

A use-case brief records who needs a change, what problem it addresses, the intended outcome, and the evidence needed for a decision. It connects an idea to a bounded investigation or trial. A completed document does not itself authorize access, spending, deployment, or a live experiment.

For an invoice-search proposal, name the purchasing clerk, eligible invoices, current lookup process, and desired reduction in active preparation time. Specify that the clerk verifies the evidence and that payment approval stays with its current owner. Include the comparison method, timing records, quality limits, unresolved questions, and people responsible.

A useful brief can say “baseline unknown; measure with the service owner before testing.” Inventing an eight-minute baseline would make the document look complete while weakening the decision. Distinguish observations, planning assumptions, targets, and approvals.

Revise the brief when evidence changes the scope or expected benefit. Keep the earlier version and reason for the change. Detailed implementation specifications can support the brief without replacing its explanation of the user outcome.

Related reference: GOV.UK service measurement guidance. Examples and calculations here are illustrative.