Testing and acceptance (FAT and SAT)

Testing and acceptance (FAT and SAT) are tests that formally confirm that an installation or piece of equipment works in line with the requirements set out in the contract and specification. They are carried out according to a test plan agreed in advance, and the results are recorded in test reports signed by both parties.

There are two main types of acceptance tests:

• FAT (Factory Acceptance Test) is carried out at the manufacturer’s or contractor’s premises before the equipment is shipped to the client. Client representatives check the workmanship, documentation and operation, often using water or simulation. Faults found at this stage are fixed faster and at lower cost than after delivery.
• SAT (Site Acceptance Test) is carried out at the client’s plant after the installation has been mounted and connected to utilities, power and other equipment. It checks whether everything works together under real operating conditions.

Successful acceptance tests and commissioning are usually followed by final acceptance, from which the warranty period begins and the installation is formally handed over to the client.

FAT example: A contractor has built a flavour and colourant dosing module for a pet food manufacturer. Before shipment, the client visits the workshop. The module is run on water, and the client checks whether the dosing pumps deliver exactly the set quantities, whether the valves switch in the correct sequence and whether the operator panel shows the correct values. It turns out that one of the pumps is overdosing by a few percent. The contractor corrects the settings on the spot, and the module is shipped to the client in full working order.

SAT example: After delivery, the same module is connected to the client’s installation: to its power supply, compressed air and the pet food line. Only here can you see whether everything works together under real conditions, for example whether the plant’s compressed air pressure matches what was assumed in the design and whether the module exchanges signals correctly with the rest of the line.