Difference Between FAT and SAT

Difference Between FAT and SAT

FAT and SAT are two types of testing that are frequently utilized in industrial, manufacturing, & engineering projects, notably for equipment & control systems.

Factory Acceptance Test (FAT)

Testing is performed at the manufacturer’s (or) supplier’s facility before the equipment is supplied to the client.

Purpose:

Prior to delivery, ensure that the equipment/system meets design standards and performs properly. Catch faults early to save costly on-site repairs.

Includes:

  • Functionality tests.
  • Control system logic verification
  • Simulated inputs and outputs.
  • Documentation review

Performed By:

Vendor/manufacturer, with (or) without the consumer present.

Site Acceptance Test (SAT)

Testing is performed at the final installation site, once the system has been delivered & installed.

Purpose:

Ensure system functionality in real-world operations. Confirm the integration with other systems.

Includes:

  • Re-testing of functions examined during FAT.
  • Power-up and I/O checks.
  • Integration with external systems.
  • Environmental performance (temperature, humidity, network)

Performed By:

Customer or end-user, typically with vendor assistance.

If you’re managing a project that includes both, the typical approach is:

FAT Shipment→Installation→SAT →Commissioning