Field Assessment Test (FAT, also referred as Field Trial Tests)- Field Assessment test is a method of acceptance testing where the owner of the equipment performs the full scales trials tests on the equipment and evaluates the performance with respect to the designed parameters agreed between the vendor and the owner.
Normally - the FAT tests are done multiple times as there are always suggestions or points that are to be corrected before the owner can assume the complete responsibility of the equipment. All the observations of the Owner are records and depending upon the resolution agreed are to be corrected.
After a number of FAT Tests, there may be still be points which are to be corrected but which doesn't impact the functionality of the system. These points are referred as Punch List points are their closure is required for the contract closure and the final payment to the vendor.