Guide
Factory acceptance test (FAT): a buyer’s guide for equipment from China
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What a Factory Acceptance Test actually is
The Factory Acceptance Test is the contract-defined acceptance event held at the manufacturer’s premises before shipment. It verifies the equipment against what was contracted: the technical specification, the drawings, the performance requirements, the certifications, and the documentation package, through the tests and checks agreed for the FAT. A clean FAT means the agreed checks passed and the findings raised at the factory were corrected or formally dispositioned before the equipment crossed a border; what the FAT signature commits the buyer to is set by the contract. The FAT is one event in the broader factory-control programme, and pre-shipment checks of packing and loading may still follow it. The earlier checkpoints (covered below) are what make the FAT itself efficient rather than the only line of defence.
For a deeper definition and the breakdown of what a FAT actually covers in practice, see what is a factory acceptance test (FAT)?. For the twelve-section working checklist Sinospect applies on the day: readiness, document requests, test plan, identity, functional witnessing, non-conformities and release decision, see the factory acceptance test checklist. And for the boundary between the factory test and the site test: what each verifies, what each signature commits the buyer to, see FAT vs SAT: the difference between a factory acceptance test and a site acceptance test. And for the partial discharge test specifically — when it belongs in the FAT for high-voltage equipment such as transformers, switchgear and cables — see partial discharge (PD) testing in a factory acceptance test. And if the practical obstacle is that nobody on your side can travel to the test, see whether an independent engineer can attend the FAT for you, and what controlled witnessing has to mean to be worth delegating.
What this test is called elsewhere
Related factory-control activities travel under overlapping names, but the label alone does not define the assignment. A buyer placing a first equipment order and a source inspector working an EPC package may be describing the same factory hold point or different layers of control. The table maps each term to the scope that must be confirmed in writing.
| Term you may see | Where it comes from | How it maps to FAT |
|---|---|---|
| Factory acceptance test (FAT) | General industrial and EPC contracts | The reference term used throughout this guide |
| Factory witness test, witnessed factory test | Buyer and supplier correspondence, equipment quotations | Only when the protocol, criteria, witness role, evidence, authority and release decision define it as the FAT |
| Source inspection | EPC, oil and gas, and owner’s-engineer procurement | Broader: inspection carried out at the point of manufacture rather than on receipt. The FAT is one witness point inside a source-inspection scope, and packing or loading checks may follow it |
| Vendor inspection, vendor surveillance | EPC, utility and owner procurement procedures | Broader again: the surveillance programme run across a vendor’s production against an approved ITP, with the FAT as one witness point inside it |
| Third-party inspection (TPI) | Procurement procedures, lender and insurer requirements | Names who performs the inspection — a party independent of both buyer and supplier — rather than what is tested |
| Witness point, hold point, review point | The inspection and test plan (ITP) | Positions in the ITP, not tests. A hold point stops work until the party named in the ITP releases it; a witness point requires that party to be notified and invited, and work may continue if it does not attend within the agreed notice |
| Réception en usine | French-language contracts and specifications | Yes — the standard French term for the same factory acceptance event |
| Site acceptance test (SAT) | The same contracts, one stage later | No. The SAT runs at your own site after installation — see FAT vs SAT |
| Expediting | EPC and project procurement | No. Expediting tracks whether the equipment will be ready on time; it does not verify what the equipment does |
The distinction that matters commercially is between the words that name the event (FAT, witness test, réception en usine), the words that name the programme the event sits inside (source inspection, vendor surveillance), and the words that name who attends (third-party inspection). A purchase order that says only “inspection” has settled none of the three, and that is where most acceptance arguments start.
Why FAT matters for industrial procurement from China
Three reasons FAT is structurally more important when the manufacturer is in China and the project is on another continent:
- Cost asymmetry of late discovery. A non-conformity caught at the factory costs hours of supplier time; the same non-conformity discovered after shipping, customs clearance, transport to site, and installation labour costs materially more, with schedule consequences as well as direct cost.
- Documentation acceptance for lenders and end clients. Project-financed and lender-monitored projects require dated, signed test records that can be incorporated into the project handover dossier. The FAT is when those records are generated, and when a Chinese supplier’s documentation is reconciled to the contract language, the applicable standard, and, for a regulated application such as EU-GMP, the qualification package the end client will be audited against.
- Negotiating posture during corrective action. Suppliers are far more responsive to corrective-action requests when the equipment is still in their factory, the payment milestone is unmet, and the relationship to their next contract is shaped by how they handle the current one.
The factory-control programme around the FAT
A strong factory-control programme is a sequence of checkpoints spread across the production cycle. The contract and the inspection and test plan set which checkpoints apply and in what order; a common sequence is:
- Pre-production review: drawings, material certificates, sub-supplier qualifications, and the inspection and test plan are reviewed before manufacturing starts.
- In-process inspection: work-in-progress checkpoints during manufacturing (welding, machining, sub-assembly), so non-conformities are caught before they are buried inside a finished unit.
- FAT witnessing: the formal performance testing of the finished equipment against the specification, witnessed by the parties the contract names, generating the dated and signed FAT report.
- Pre-shipment verification: final visual inspection, packing review, documentation cross-check against the contract and the certificates, container loading inspection where relevant.
The FAT itself is one acceptance event in this sequence, and one of several test/handover events across the equipment lifecycle. The factory, site and integration tests (FAT, SAT and SIT) are formally defined for process-automation systems in IEC/ANSI/ISA 62381; the table below disambiguates these and the surrounding events that are often loosely grouped together. For one-line definitions of these and the other terms used across this cluster, see the procurement and inspection glossary.
| Term | Where it happens | What it checks | Output |
|---|---|---|---|
| In-process inspection | During manufacturing | Work-in-progress (welding, machining, sub-assembly) | Inspection report |
| Pre-shipment inspection (PSI) | Before shipment, at factory | Quantity, packing, visible conformity, documentation | PSI report |
| Factory Acceptance Test (FAT) | At factory, before acceptance/shipment | Contract-defined routine, functional, and performance tests; references to type-test reports where design-level testing applies | Signed FAT report |
| Site Acceptance Test (SAT) | At buyer’s site after delivery | Installed performance under operating conditions | SAT report |
| Site Integration Test (SIT) | At site, across system boundaries | Correct interaction between subsystems and with the wider plant / control system | SIT report |
| Commissioning | At site, before handover | Bringing the installed equipment into operation: energising, loop checks, calibration and trial runs; the contract sets whether the SAT runs during or after it | Commissioning records |
What a FAT delivers in writing
The output of a FAT is a documentation package. A complete FAT package includes: the inspection and test plan that was followed, the test results against each specification line item, the calibration certificates for the test instruments used, photographs of test setup and equipment condition, the non-conformity log with each finding classified by severity, the corrective-action register with dates and sign-off, and the signed FAT report or FAT certificate in the form the contract requires.
That package is what the buyer presents to the lender, the end client, or the project insurer to support release of payment milestones and the eventual handover.
Common reasons a FAT fails
- The inspection and test plan was not agreed in writing before manufacturing started, so the supplier ran the tests they considered standard rather than the tests the buyer expected.
- Calibration certificates for critical test instruments were missing or expired, so the affected readings could not be relied on until the instruments were verified or the tests repeated.
- Sub-supplier components arrived late, were tested under time pressure, and were waved through with non-conformities the supplier preferred not to surface.
- Documentation deliverables (manuals, electrical schemes, spare-parts lists) were prepared at the last minute and do not match the as-built equipment.
- The witness’s role and escalation route were not agreed, so non-conformities were noted but never reached the party with authority to hold release.
When FAT should be planned in the project timeline
FAT planning starts at contract signature, not at the end of manufacturing. The inspection and test plan is agreed with the supplier as part of contract execution. The witness party is identified and committed in time to be available when the equipment is ready. Lender or end-client participation requirements are clarified early so the right people are present.
A FAT that is scheduled three weeks before the contracted shipment date, rather than three days, leaves room to address non-conformities without forcing the buyer to choose between accepting defects and triggering a late delivery.
How Sinospect supports factory acceptance testing
When Sinospect supplies the equipment from China as the accountable supplier, the agreed inspection sequence supports its own quality-control decision before release of the factory’s final balance. Deposits and verified milestones follow the order terms. For buyers sourcing direct, Sinospect carries out the commissioned controls on the client’s order: review of the inspection and test plan, in-process inspection visits during manufacturing, pre-shipment verification, and factory acceptance testing in China, with dated, photographed reports and defect-classified corrective-action tracking through to resolution. For transformer orders, switchgear and control panels, and contracts where partial discharge measurement decides acceptance, dedicated witness scopes are described under transformer FAT witnessing, switchgear & panel FAT witnessing and PD test witnessing. Where the order is a multi-discipline project package rather than a single machine, or a cleanroom system, or switchgear whose acceptance turns on partial-discharge behaviour, the deeper scopes are FAT for EPC procurement packages, cleanroom systems FAT witnessing and switchgear and GIS partial-discharge witnessing. The work is run out of Hong Kong and Ningbo with on-the-ground capacity at the manufacturer’s site.
See how Sinospect works for the full execution method, review the field notes for examples of inspection findings, corrective evidence and decision authority, or review our commitments for the inspection methodology in detail. For the verification sequence applied at the pre-shipment stage specifically, see the pre-shipment inspection checklist.
Frequently asked questions
Is a factory witness test the same as a Factory Acceptance Test?
Not automatically. “Factory witness test” and “witnessed factory test” describe someone observing a test; they refer to the same assignment as a FAT only when the protocol, acceptance criteria, witness role, evidence, authority and release decision are agreed in writing. Source inspection and vendor surveillance name wider programmes, third-party inspection names who attends rather than what is tested, and site acceptance testing names a later event at the buyer’s site.
Is a Factory Acceptance Test the same as a pre-shipment inspection?
Related, but not identical. A pre-shipment inspection is a separate factory-control checkpoint before packing or shipment, usually focused on quantity, visible conformity, packing and documentation. A FAT is the contract-defined acceptance event, focused on the agreed tests and acceptance criteria. A strong factory-control programme may include both.
What test results should the buyer expect in writing?
Routine testing per the equipment’s applicable standards (insulation resistance and dielectric tests for electrical equipment, hydrostatic tests for pressure vessels, performance curves for pumps, etc.), references to the applicable type-test reports where design-level testing is required, the measured values against the specification, the calibration evidence for the test instruments used, photographs of the test setup, and any non-conformities with corrective actions agreed and dated.
Does the buyer have to be physically present for the FAT?
The buyer can attend in person, send a representative, appoint a third-party inspection company to witness on their behalf, or, where the contract and the tests allow it, accept a remotely witnessed FAT with live video and full documentation. A lender or end client may require an independent third-party witness.
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.
Planning a factory acceptance test in China?
Send the equipment scope, the contract test requirements and the expected FAT window. Sinospect acknowledges the request within one business day. When the file is sufficient, the initial written assessment follows within two business days with the witnessing approach, the document pack the buyer should expect, the team that would attend and a quotation.