Definition of Factory Acceptance Test (FAT)
Factory Acceptance Testing is carried out to check that the product conforms to the requirements set for it, and that it is fit for its intended purpose.
If the test is passed then the product is said to be Mechanically Complete (MC) and can be passed on to the next part of the process, in which the product is installed, commissioned and put into operation. The commissioning team is central to the FAT process.
Any non-conformity discovered during FAT needs to be clearly documented, in a NonConformance Report (NCR).
These nonconformances, and any other issues discovered, are often also registered separately as punch items and followed up on by the commissioning team.
EFAT is a similar term, meaning Extended Factory Acceptance Test