Scenario: pay 6 invoices from 3 currencies
Ask the participant to select the right target currency, review the aggregate, and submit within the active lock period.
Success means the user can explain what is locked, what is not, and what will reach the checker.
Questions that expose system ambiguity
“Which rate is used?” “Why is this currency selectable?” “What changes at the next refresh?” “Can I pay without conversion?”
If participants answer from the interface instead of from domain knowledge, the model is doing its job.
Evidence to capture
Time to first confident selection, wrong-currency attempts, rate-lock explanation accuracy, recovery success, and stakeholder acceptance of the approval summary.
Pair task data with the risk owner’s confidence in auditability and exception handling.