FAT (Factory Acceptance Test) is a fundamental test that is performed at the manufacturer’s plant before a weighing machine or system (such as a checkweigher, a weigh price labeler or an industrial metal detector), be delivered to the customer for final installation. The main objective of FAT is to verify that the machinery meets all the required technical and operational specifications, ensuring that it functions properly in all its parts before being put into service. FAT testing follows a structured procedure, performed by certified entities, which involves several verification steps, both with regard to the mechanical and electronic components, as well as for the weighing software. This test gives the customer confidence that the machine will function exactly as intended, minimizing the risk of malfunctions or problems once the system is in operation. In addition to FAT, there is also the SAT test (Site Acceptance Test), which takes place after delivery and installation of the machine at the customer’s site. While FAT focuses on the manufacturer’s verification of the system, SAT is intended to test the equipment in the actual operational context where it will actually be used. Both tests are essential to ensure the quality and reliability of systems, but they operate in different stages and contexts of the product life cycle.