Lifecycles
Checkout, Borrow, Acknowledge, and Return
Preserve actor accountability and physical custody through partial and exceptional returns.
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Identities that must remain separate
- Actor: authenticated human who performs the system action; server-derived and immutable.
- Accountable custodian: person responsible for the item.
- Receiver or witness: person confirming physical handoff where required.
- Approver: different authorized person for dual-control actions.
Self-checkout locks the actor as accountable user. Operator-mediated checkout retains the operator as actor and requires an explicit custodian plus acknowledgement.
Checkout
Verify identity, availability, condition, quantity, issue location, purpose, and due date. Serialized items cannot have overlapping active custody. Quantity items cannot exceed available balance. Retry with the same idempotency key rather than creating a second assignment.
Return
Scan the item, enter returned quantity and destination, inspect condition, and record loss or damage. Partial returns keep the remaining assignment active and restore only the returned quantity. Never edit an earlier event; corrections append compensating evidence.