Make the FAT prove the machine meets the requirement
A machine running in front of the buyer is not automatically a Factory Acceptance Test. A useful FAT links the contracted requirement to a defined test condition, measured result, acceptance limit and traceable evidence before shipment or final payment.
When should FAT acceptance criteria be written?
Before the machine is complete - ideally with the specification and purchase contract. That is when the owner and builder can still agree on what success means, what materials and utilities are required and which results block release.
What should a FAT record?
Machine identity and revision, test setup, representative material or product, instruments, measured results, pass/fail criteria, deviations, corrective actions, outstanding punch-list items and the release decision.
What is the difference between FAT and SAT?
FAT verifies as much as practical at the builder before shipment. SAT verifies installation and performance in the owner’s actual site environment, utilities and interfaces. Site-dependent risks should not be disguised as factory tests.
Why is video evidence not enough?
Video can document an event, but it does not by itself establish the drawing revision, material, test condition, measured value, allowable limit or status of a deviation. Traceability matters more than spectacle.