What is the difference between SAT and fat?
FAT Definition
FAT represents a manufacturer-executed testing process which runs after design qualification and it takes place at the production facility to validate that vendors have completed their contractual requirements and regulatory specifications and client needs.
SAT Definition
A Site Acceptance Test (SAT) stands as the qualification stage after FAT to perform equipment testing sequences directly at the owner representative’s site. The SAT serves to prove that equipment and system delivery brought untainted products unaffected by transfer methods.
The conditions during these tests distinguish themselves through multiple distinctions that include:
- While the system manufacturer operates at the FAT location the owner representative conducts testing through the SAT at their premises.
- The sites for manufacture and vendor maintain different temperatures and humidity measurements. Such real utility conditions like steam and compressed air need to be provided using actual equipment only at the SAT stage which takes place at the owner’s facilities.
- The SAT contains basic documentation whereas the FAT needs extensive records.
Comparison between SAT (Site Acceptance Test) and FAT (Factory Acceptance Test)
| Aspect | FAT (Factory Acceptance Test) | SAT (Site Acceptance Test) |
|---|---|---|
| Location | Vendor’s factory or testing facility | Installation site (plant or facility) |
| Purpose | Verify system functionality before shipment | Site tests should confirm the proper installation alongside site integration and operation performance validation. |
| Conditions | Simulated conditions | Real-world site conditions |
| Scope | Functional tests, configuration checks, internal wiring verification | The framework includes Loop checks together with field integration and system commissioning and communication tests. |
| Participants | The testing team includes vendor representatives together with client representatives and engineering staff members. | The testing group comprises end-user personnel and site engineering departments together with vendor support staff. |
| Testing Focus | The system development verifies that assembly achieves design specifications. | The process focuses on correct installation practices and site-based system performance together with equipment integration. |
| Key Activities | Hardware/software testing, functional validation, simulation, I/O checks | Loop checks, interlock testing, communication validation, system tuning |
| Risk Mitigation | Identifies manufacturing defects before shipment | Ensures system is installed and operates correctly before commissioning |