What is a factory acceptance test (FAT)?
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Sinospect supplies industrial equipment from China as the principal, with the FAT as its own release gate; for a direct purchase it attends the FAT for you. Send your FAT plan for review →
Why must a FAT be defined in the contract?
A Factory Acceptance Test is a defined obligation in the purchase contract: an inspection and test plan agreed between buyer and supplier, naming the tests to be performed, the standards they will follow, the measurement criteria, the equipment to be used, and the witnessing arrangement. The FAT exists in the form the contract defines.
That contractual basis is what gives the FAT its weight. In many contracts, FAT acceptance is tied to a payment, shipment, or documentation milestone; where the contract names the remedies, a failed FAT triggers them (corrective action, re-test, deferred shipment) without renegotiation. A FAT anchored in the contract becomes one of the procurement’s important control points.
What does a FAT actually check?
A complete FAT verifies the equipment against four classes of contract content:
- The technical specification: dimensions, materials, components, configuration, labelling, and visual condition match the agreed specification.
- Performance requirements: measured performance (capacity, efficiency, accuracy, response, whatever the equipment’s output metric is) meets the contracted values under the test conditions defined.
- Certifications and compliance: certificates, type-test reports, and compliance documentation are present, authentic, and apply to the equipment being shipped.
- Documentation package: the manuals, drawings, spare-parts lists, calibration certificates and project-specific documents due at FAT are present in the agreed revision and match the equipment as tested; documents that can only be final later, such as drawings updated after site changes, are listed with their due date.
What types of tests can be included in a FAT?
The specific tests depend on the equipment and the applicable standard. Some common categories:
- Routine tests: required by the applicable product standard on each unit. For a transformer, establish the routine-test list from the governing IEC 60076 part and edition, transformer type and voltage; do not apply one generic list to every transformer.
- Type tests: performed on representative equipment to assess the design against the applicable product standard. Check that the report covers the ordered design and later changes, and whether further testing is required by the standard or contract.
- Performance tests: measured against the contract’s performance values (efficiency curves, throughput, accuracy under load).
- Functional tests: operational sequences, control system behaviour, interlocks, alarms, and emergency stops, run end-to-end.
- Visual and dimensional inspection: final check of fit, finish, labelling, marking, and packing.
For HV equipment — transformers, switchgear, HV cables — see how partial discharge (PD) testing at FAT is specified, witnessed and accepted.
What a FAT actually catches when the works is in China
The definition is the easy part. What makes a FAT worth attending is the gap between what a supplier demonstrates and what the contract requires, and that gap is widest when the buyer is on another continent and the works is in China. A FAT catches the failures that survive a supplier’s own QC because they are matters of contract interpretation, not workmanship:
- A type-test or material report that applies to a different design revision, batch or model than the unit being shipped.
- Calibration certificates for the test instruments that do not show metrological traceability to national or international measurement standards, or that come from a calibration source the contract does not accept.
- Nameplate, tag and marking that do not match the contract specification or the approved drawings.
- A documentation set delivered only in Chinese, or missing the certificates a regulated application such as EU-GMP requires.
- A monitoring, alarm or safety feature quietly dropped, with a plausible-sounding reason for why it is not needed.
That last one is the most common, and the most expensive to concede.
For a regulated application the documentation package is part of the equipment’s qualification, not an afterthought. A unit that performs well on the factory floor can still fail acceptance on documentation alone, which is why a FAT verifies the certificates and records as rigorously as the function.
Who should attend a FAT, and what are their roles?
A typical attended FAT involves the supplier’s testing team running the tests, the supplier’s QC representative confirming results against the procedure, the buyer or buyer’s representative observing and signing the record, and, for lender- or end-client-monitored projects, a third-party inspector delegated to witness and document the agreed scope. An inspector may exercise limited acceptance authority only when the contract or a written delegation expressly grants it; otherwise the buyer retains acceptance, deviation and release decisions. Each role is named in the inspection and test plan, and each signature on the FAT report and the FAT certificate carries a specific meaning.
How does FAT differ from the supplier’s internal QC?
Internal QC is the supplier’s own quality control during and after manufacturing. It is independent of the buyer’s presence, follows the supplier’s procedures, and produces internal records. FAT is the contract-defined, buyer-facing verification event that draws on the QC results but adds witnessed checks, a contract-anchored test scope, and a signed record of findings and results. That record does not by itself constitute buyer acceptance unless the contract expressly gives it that effect. The strength of a supplier’s internal QC largely determines how readily it passes FAT.
How does FAT differ from SAT and commissioning?
FAT happens at the manufacturer’s premises before shipment. SAT, the Site Acceptance Test, happens at the buyer’s installation site after delivery, verifying that the equipment performs under operating conditions and in its installed configuration. Commissioning is the site work that brings the installed equipment into operation, such as energising, loop checks, calibration of on-site references and trial runs; the contract sets whether the SAT runs during or after it, and which event starts the warranty. FAT is the earlier of the two acceptance tests, and a well-run FAT reduces what SAT and commissioning have to discover. For the full comparison, what each test covers, what each signature commits the buyer to, and why passing FAT is no guarantee of passing SAT, see FAT vs SAT: the difference between a factory acceptance test and a site acceptance test.
| Test | Where / when | What it verifies | Defining reference |
|---|---|---|---|
| Factory acceptance test (FAT) | Manufacturer’s works, before shipment | Build and function against the contractual specification, under factory utilities and simulated signals | IEC/ANSI/ISA 62381 |
| Pre-shipment inspection (PSI) | Factory or warehouse before loading, at the stage the inspection scope sets (after FAT where both are contracted) | What actually ships: quantity, packing, preservation, marking and punch-item closure, with no substitution | Buyer / third-party QC scope (e.g. ISO 2859-1 sampling) |
| Site acceptance test (SAT) | Project site after installation, during or after commissioning as the contract sets | Installed performance under real utilities, process media and plant integration | IEC/ANSI/ISA 62381 |
| Site integration test (SIT) | Project site, across equipment and system boundaries | Correct interaction between subsystems and with the wider plant / control system | IEC/ANSI/ISA 62381 |
For the working document applied on the day, the readiness, identity, witnessing and release steps of the factory test itself, see the factory acceptance test checklist.
How Sinospect uses the FAT
When Sinospect supplies the equipment from China as the principal, the FAT is a gate in its own contract with the manufacturer: the factory’s final balance is released after the agreed evidence meets that gate, not before. For buyers who purchase direct and want execution control only, Sinospect runs the same FAT on the client’s own order: reviewing the inspection and test plan against the contract, attending at the manufacturer’s premises, witnessing the agreed tests, delivering the signed FAT package and recommending hold, re-test or release while the buyer retains the commercial decision. The work is run from Hong Kong and Ningbo, embedded in the procurement rather than sold as a one-off. This is the engagement Sinospect offers as factory acceptance testing in China.
See the cluster guide on factory acceptance testing for the broader workflow, or how Sinospect works for the full execution method. Where the order also includes a pre-shipment inspection, the same team can run pre-shipment inspection in China after the FAT to confirm that what passed the test is what actually ships.
Frequently asked questions
Is the term FAT standardised in international procurement?
FAT is a widely used industry term rather than a single standardised procedure. The FAT, SAT and SIT framework itself is defined for process-automation systems in IEC/ANSI/ISA 62381 (with the ISA-105 series covering commissioning and loop checks), while the specific tests that apply appear in many category standards and codes: IEC for electrical equipment, ASME for pressure vessels, API for oil-and-gas equipment, IEEE for some power equipment, each defining the tests for its product category. The contract names the standard the FAT will follow.
Can a fully remote FAT be considered equivalent to an attended one?
It can be, where the contract allows remote attendance and the agreed tests can be observed and recorded remotely: live video from several angles, full documentation and recorded testing. The party that holds acceptance under the contract decides whether a remote FAT is acceptable; a lender, an end client or tests whose evidence video cannot capture may require a witness physically present.
How long does a FAT take?
From half a day for a small piece of standard equipment to a full week for a large bespoke installation. The duration is driven by the test scope agreed in the inspection and test plan, not by a standard convention. A poorly-planned FAT often runs over its allotted time because non-conformities surface during testing and need on-the-spot resolution.
What happens to the FAT documentation after the test?
The signed FAT report, test records, calibration certificates, photographs, and corrective-action register are incorporated into the equipment’s lifecycle documentation: the as-built dossier handed to the end client, the installation and commissioning reference, the warranty baseline, and, for lender-financed projects, the disbursement support package.
FAT working resources
Practical resources for this stage, available without an email gate.
The FAT is one gate in the order
Order failures can start before the factory visit: an offer that drifts from the requirement, or a manufacturer whose claims need proof. These services act before the test date.
- China supplier evaluation
Identity and capability findings from a desk check, with video verification and factory audit options.
- Supplier due diligence before you pay
Both entities, the payment instructions, the negotiator and the capability evidence, in a report four business days after payment and the last document.
- Buy from Sinospect
Sinospect supplies the equipment as your counterparty, and the FAT becomes Sinospect’s own release gate.
Preparing for a first FAT in China?
Send the equipment type and where the order stands. Sinospect acknowledges the request within one business day. When the file is sufficient, the initial written assessment follows within two business days with what the FAT should cover, the documents to agree with the supplier, how on-site attendance would work and a quotation.