What the SAT Is — and Where It Fits
The Site Acceptance Test sits between the Factory Acceptance Test and the Installation Qualification in the GAMP 5 validation lifecycle. It is executed at the client's site after the system has been delivered and installed, but before formal IQ testing begins. Its purpose is to confirm that the system survived delivery and installation without damage or configuration loss, and that it is functioning correctly in the actual production environment before the formal qualification record is opened.
The SAT is not always mandatory — the V-model doesn't position it as a formal qualification phase. But in practice, any experienced validation team running a complex PLC/SCADA installation will include one, because it catches the issues that routinely occur during transport and commissioning before they become formal IQ deviations.
FAT = system works correctly at the supplier's factory, tested against the FDS. SAT = system works correctly at site after installation, before formal qualification record opens. IQ = formal documented evidence that the system is installed correctly, as a controlled quality record.
What the SAT Tests
The SAT is not a repeat of the FAT. It is specifically targeted at issues that arise during shipping, installation, and site integration — things that were correct at the factory but may have changed in transit or during panel installation:
- Physical condition — no damaged equipment, loose connections, bent I/O modules, damaged screens
- Power-on and boot sequence — all components start correctly in the site environment
- Network connectivity — PLCs, HMI, SCADA server, historian all communicating correctly on site network
- IP address configuration — all devices at their specified site addresses (different from factory test addresses)
- Software version verification — PLC program, SCADA application, and OS versions match FAT-tested versions
- I/O loop checks — field instruments correctly wired to the right PLC I/O channels (critical — wiring changes happen during installation)
- Alarm and interlock basic function checks — critical alarms activate correctly with field instruments connected
- Integration with site systems — historian writing to the correct database, LIMS interface active if applicable
The Key Difference from IQ: Informal vs Formal
The SAT is executed informally — it is a commissioning activity, not a qualification activity. Issues found during the SAT are corrected before the IQ opens, not logged as IQ deviations. This is the primary reason experienced engineers insist on a SAT: it converts IQ findings into pre-IQ corrections, protecting the formal qualification record.
A wiring error discovered during SAT is fixed and re-checked before IQ. The same error discovered during IQ is a formal deviation, must be logged in the Master Deviation Ledger, requires a corrective action, may delay IQ sign-off, and creates a permanent record of a finding that could raise questions in future audits.
The SAT Protocol
Unlike the FAT, IQ, OQ, and PQ, the SAT protocol does not need to be a formally approved GMP-controlled document. It is typically a working document used by the commissioning team. It should however contain:
- System configuration baseline (software versions, IP addresses) to verify against
- I/O loop check sheet — every I/O point, its tag name, its field instrument, and a verified/not-verified status
- Network connectivity test results
- Basic functional check results for critical alarms and interlocks
- List of any issues found and their resolution before IQ
- Sign-off by commissioning lead confirming system is ready for IQ
The SAT template includes a full I/O loop check sheet (pre-formatted for up to 200 I/O points), network connectivity test table, software version verification record, and a pre-IQ sign-off page. It is designed to be used as a working document during commissioning — not a controlled GMP record — while producing the evidence needed to confirm the system is IQ-ready.