Glossary · Engineering, integration and validation
Factory acceptance test (FAT)
Also known as: FAT
German: Werksabnahme (FAT)
In automation projects, a factory acceptance test (FAT) is the test of a machine, skid or automation system at the supplier's premises, usually witnessed by the customer, to show that it meets the agreed specifications before shipment. Passing the FAT is often a contractual milestone.
- Validation
- Standards
In one sentence
A factory acceptance test (FAT) checks a machine or automation system at the supplier's site against the agreed specifications before shipment.
Example
During the FAT, the customer's engineers run all sequences of the mixing skid with water, check the alarms and sign the punch list before the skid is shipped.
How it applies
- Project management: Supplier and customer agree on the FAT scope, test procedures, acceptance criteria and how open points are handled. IEC 62381 describes FAT, SAT and site integration test for automation systems in the process industry.
- Commissioning: Defects found at the FAT are fixed at the factory, which is cheaper than on site. Tests that depend on the installation environment move to the Site acceptance test (SAT).
- Quality: Each test step is recorded in a Test protocol, with deviations and their resolution.
- Documentation: The FAT is a good moment to check the draft user documentation against the real machine; the documentation team can also collect screenshots and verify that warning labels match the manual.
FAT vs. SAT
The FAT takes place at the supplier's premises before shipment; the SAT takes place at the customer's site after installation and shows that the system works in its real environment. Passing a FAT confirms agreed functions under test conditions; it does not replace the manufacturer's risk assessment or conformity assessment.