ACCEPTANCE DECISION
Factory Acceptance Test vs supplier demonstration
A demonstration proves that something happened. A FAT should prove that an agreed requirement was met. The difference is traceability: requirement, test condition, measurement, acceptance limit, result and disposition.
What makes a FAT more than a demo?
An approved test procedure, identified equipment revision, representative test conditions, calibrated or suitable measurement methods, pass/fail criteria and recorded results.
What should happen when a requirement fails?
The deviation should become a controlled item: description, impact, corrective action, owner, retest requirement and release status. Shipment pressure should not silently redefine the acceptance criterion.
Why define this before the test date?
Because once the machine is built and shipment is booked, every undefined requirement becomes a negotiation under schedule pressure.