Equipment Qualification
FAT & SAT Frequently Asked Questions

No — SAT should still be performed even after a successful FAT, because SAT verifies the equipment functions correctly in its actual installed environment, interfacing with site utilities, facility systems, and other equipment, none of which can be fully replicated at the vendor's factory.

A risk-based approach under ASTM E2500 can reduce the depth of SAT testing by leveraging FAT results for functions that are genuinely environment-independent, but eliminating SAT altogether is rarely defensible for GxP-critical equipment, since transport, installation, and site utility connections all introduce risks FAT cannot detect.

Engineering typically leads FAT witnessing to verify technical and functional performance against the specification, while QA involvement is expected for GxP-critical equipment to confirm the test approach, acceptance criteria, and documentation meet quality system requirements — the level of QA involvement should scale with the equipment's GxP impact.

For lower-risk, indirect-impact equipment, QA may review FAT documentation after the fact rather than witness testing in person. For high-risk, direct-impact equipment, on-site QA witnessing during FAT is generally expected.

Functions that are independent of the installation environment — core mechanical operation, internal software logic, alarm configuration, and component-level performance — are typically fully tested at FAT and not repeated at SAT, while anything dependent on site conditions must be verified at SAT regardless of FAT results.

• Internal mechanical and electrical function tests independent of site utilities.
• Software and control logic testing that does not depend on the site network or interfacing systems.
• Alarm and interlock configuration testing performed under controlled factory conditions.
• Component and subsystem performance verification against the equipment specification.

Not every piece of equipment needs a formal FAT and SAT — the decision should be risk-based, driven by the equipment's GxP impact, complexity, and novelty, with simple, standard, low-risk equipment often qualified through IQ/OQ alone without a separate factory or site acceptance testing phase.

FAT and SAT test scripts should be written after the User Requirements Specification is finalized and approved, because every test in both scripts should trace directly back to a specific, approved requirement — writing scripts before the URS is settled risks testing against requirements that later change.

In practice, draft scripts are often developed in parallel with a near-final URS to save time, but they should not be formally approved and locked until the URS itself is approved, to preserve traceability between requirements and test coverage.

Equipment should not ship to site with an unresolved FAT failure that affects a GxP-critical function — the failure should be investigated, corrected, and successfully retested before shipment, or shipped only with a documented, QA-approved justification and a clear plan for resolution and retesting at or before SAT.

Shipping equipment with known unresolved failures and hoping to catch them at SAT is a common but risky shortcut, because it moves problem resolution to a location with fewer vendor engineering resources on hand and can delay the entire qualification schedule if the issue turns out to be more complex than expected.

A FAT deviation is typically resolved through the vendor's own quality process before the equipment ships, while a SAT deviation is managed through the receiving site's deviation and change control system, since by that point the equipment is under the site's quality umbrella.

Some organisations still require FAT deviations to be logged in the site's own deviation system if they affect a GxP-critical function, to preserve a complete record even though the resolution work happens at the vendor's facility.

Yes — remote or virtual FAT, conducted via live video with the site team observing and directing testing performed by vendor personnel, is generally acceptable to regulators provided the approach is justified by risk assessment, the remote witnesses can genuinely verify the tests performed, and the session is documented to the same standard as an in-person FAT.

An acceptable punch list item is a minor, non-GxP-critical issue — such as a cosmetic defect or a documentation formatting correction — that doesn't affect the equipment's function or the validity of the test results obtained; anything affecting a GxP-critical function, safety, or the accuracy of a test result must be resolved and retested before FAT can be signed off.

Yes — if equipment shows evidence of transit damage, or was disassembled and reassembled for shipping, the functions potentially affected by that damage or reassembly must be retested at SAT, even if those same functions were already verified during FAT, because the FAT results no longer represent the equipment's current state.

Yes — under a risk-based approach such as ASTM E2500, documented and verified FAT results can be leveraged to reduce duplicate testing during IQ or OQ, provided the FAT was performed under an approved protocol, witnessed and documented to GxP standards, and the functions being leveraged are demonstrably unaffected by installation at site.

This leveraging must be explicitly justified in the qualification strategy or protocol, referencing the specific FAT test results being relied upon, rather than assumed by default — an inspector will expect to see the rationale, not just the reduced test count.

Core automation and control logic on the equipment is typically tested at FAT as part of verifying the equipment functions correctly, but this does not replace formal Computer System Validation for any GxP-critical software component — FAT testing of automation should feed into, not substitute for, the CSV lifecycle for that system.

The approved and executed FAT protocol, including all raw test data, any deviation records and their resolution, the final FAT report, and calibration certificates for any instruments used during testing should all travel with the equipment or be transmitted to the site before SAT begins.

• Approved and executed FAT protocol with raw data.
• FAT deviation records and evidence of resolution.
• Final FAT summary report with conclusion and sign-off.
• Calibration certificates for instruments used during FAT testing.
• As-built drawings or configuration records reflecting the equipment as tested.

QA should approve the decision to reduce SAT scope based on FAT evidence, typically through review and sign-off of the qualification strategy or a specific risk assessment that documents which FAT results are being leveraged and why, before the reduced SAT protocol is executed.

Yes — any reduction in SAT scope based on FAT results should be supported by a documented risk assessment that identifies which specific functions are being leveraged, why they are considered installation-independent, and what residual risk, if any, is being accepted by not repeating the test at site.

FAT protocols are typically co-signed by the vendor's quality representative and the customer's engineering and QA representatives who witnessed testing, while SAT protocols are signed by the site's engineering executor, a QA reviewer, and a final QA approver, following the site's own protocol approval hierarchy.

Inspectors typically check that FAT and SAT protocols were approved before execution, that test results trace back to specific approved requirements, that any deviations were properly investigated and resolved, and that the rationale for any SAT scope reduction based on FAT results is documented and risk-justified rather than simply assumed.

A frequent finding is a SAT protocol that omits tests without any documented justification tracing back to FAT — this reads as an undocumented gap rather than a deliberate, risk-based decision, even if the underlying reasoning was sound.

FAT and SAT records should be retained for at least as long as the qualification records for the equipment they support — commonly the equipment's operational lifetime plus the site's standard record retention period after decommissioning, since they form part of the equipment's foundational qualification evidence.

The most common mistake is treating FAT and SAT as generic functional demonstrations rather than GxP-traceable tests written directly against approved URS requirements — when FAT and SAT aren't clearly traceable to requirements, teams can't confidently leverage the results later during IQ/OQ, and end up re-testing everything at site anyway.

This usually surfaces during protocol writing for IQ/OQ, when the qualification team realises FAT results can't be cited as evidence because the original test scripts never referenced the specific requirement being verified.

Yes — ASTM E2500's risk-based approach shifts FAT and SAT from being treated as separate, standalone testing phases toward being an integrated part of a single verification strategy, where commissioning, FAT, and SAT data are all leveraged together against Critical Design Elements to avoid duplicating tests across the qualification lifecycle.