How to Plan Factory Acceptance Testing for a Custom-Built Containerized Equipment Package

Short Summary

An effective factory acceptance test (FAT) proves the agreed package before shipment: identity, construction, interfaces, functional performance, protective devices, alarms, documentation and outstanding actions. It does not replace site acceptance testing, transport inspection or project approvals. Start with a traceable FAT plan linked to the purchase order, approved drawings, risk controls and site operating scenarios.

The Short Answer

Plan the FAT before fabrication is complete and use it to verify the package the customer actually ordered. The test should identify the unit, approved documents and configuration; inspect workmanship; verify dimensions, interfaces and markings; test functional and protective systems; record results; and close or clearly classify every outstanding item before shipment. The FAT is strongest when it follows the project’s real operating scenarios rather than a generic checklist.

For containerized packages, the FAT boundary can include the enclosure, structural items, electrical distribution, HVAC, controls, fire and gas interfaces, equipment skids, doors, lifting provisions and documents. It must be agreed explicitly. A successful FAT does not automatically prove final installation, transport suitability, statutory approval or operation at the customer’s site.

1. Define the Acceptance Boundary and Evidence Before Testing

Begin with the contractual scope. Freeze the documents that establish what is being accepted: purchase order, technical specification, approved general arrangement, interface drawings, electrical single-line diagram, equipment datasheets, bill of materials, control narrative, inspection and test plan, inspection records and approved deviations.

Use the FAT plan to distinguish three conditions:

Requirements that can be physically tested in the factory
Requirements that can be inspected or verified by document review only
Requirements that must be verified after transport or site installation

This prevents a common problem: attempting to declare a module “fully accepted” when external utility connections, host alarms, weather exposure, foundation support, communications and operating loads do not exist in the factory.

Every test should state the precondition, test method, expected result, record, witness requirement, acceptance criterion and action if it fails. Where a simulated signal or temporary test supply is used, mark it clearly so it is not mistaken for the final site condition.

2. Confirm the Physical Package Matches the Approved Design

Verify the equipment identity, serial numbers where applicable, dimensions, mass basis, center-of-gravity marking if required, door configuration, access openings, cable and pipe entries, external interfaces, labels, coating, internal fixtures, lighting, drainage and enclosure sealing. Compare these with the latest approved drawings, not superseded sketches.

Structural and handling features require special attention. Confirm the intended lifting points, rated markings, lifting-set scope, forklift restrictions, tie-down or sea-fastening points, transport configuration and any removable items. Do not assume that corner castings or an enclosure shape establish transport approval. For freight containers used in international transport, the CSC framework covers specific testing, approval, inspection and maintenance provisions; a custom equipment package can have a different approved handling and certification basis.

Check maintainability while access is available in the factory. Open doors and panels, remove designated covers where practical, and verify access to filters, batteries, pumps, valves, control panels, service points and replaceable components. A FAT is the cheapest time to identify a blocked maintenance route or an unsafe working position.

3. Test Systems Through Realistic Operating Scenarios

The strongest FAT follows the way the package will be used. Prepare operating cases such as energization, startup, normal operation, local and remote control, loss of normal supply, emergency stop, shutdown, restart, alarm response, maintenance isolation and recovery after a component fault.

For electrical systems, confirm supply characteristics, protective-device settings, phase identification, continuity, insulation testing as applicable, functional operation of breakers and interlocks, emergency stops, UPS or battery functions where included, lighting, sockets, earthing and alarm indications. Verify that drawings, terminal labels and field devices agree.

For HVAC and ventilation, test fan rotation, airflow indication where supplied, temperature control, dampers, alarms, heaters or cooling equipment, condensation management, door interlocks and any shutdown signal. Do not claim a site-temperature performance guarantee from a brief factory run unless the agreed test conditions reproduce that duty.

For controls and automation, test each input and output in the cause-and-effect matrix. Demonstrate local controls, remote commands, permissives, alarm priority, time delays, fail-safe states, communications and manual fallback. A well-recorded input/output check is more valuable than a demonstration that only shows the system starting once.

For fire, gas, leak or other protective systems, follow the agreed safety procedure and manufacturer instructions. Demonstrate detection, alarm, shutdown and interface signals only within safe and authorized test limits. Record any functions that require final-site testing because their release, suppression, alarm or emergency-system interface cannot be fully energized in the factory.

4. Inspect Workmanship, Documentation and Configuration Control

The FAT should inspect more than performance. Check weld and fabrication records where required, coating condition, corrosion protection, penetrations, cable management, gland installation, pipe supports, insulation, guards, signage, nameplates, warning labels, housekeeping and protection of sharp edges or hot surfaces.

Review the documentation pack before shipment. It may include approved drawings, data sheets, manuals, certificates, inspection reports, material records, electrical test results, software and parameter backups, calibration certificates, spare-parts lists, packing list, preservation instructions, transport instructions, lifting information, maintenance schedule and as-built deviations.

Configuration control is essential. Record the software and firmware versions, control parameters, setpoints, password-transfer process, installed device identities and any temporary test links that must be removed. Otherwise the unit that leaves the factory may not be the configuration that passed the FAT.

5. Manage Non-Conformities Without Hiding Risk

Use a punch-list process that identifies the item, requirement, impact, responsible party, corrective action, evidence required and target closure date. Classify items by their effect on safety, performance, documentation and shipment readiness.

Do not allow a list of minor-looking open points to obscure a serious interface or safety issue. Examples of shipment blockers can include an inoperative emergency stop, missing protective-device test evidence, unverified lifting arrangement, incorrect equipment configuration, a failed leak test, inaccessible maintenance isolation, or a fire-and-gas signal that has no agreed final verification route.

If the customer accepts an item for closure after shipment, record the exact limitation and the site test or inspection that will resolve it. The goal is transparency, not a perfect-looking report.

6. Link FAT to Transport and Site Acceptance Testing

Prepare the unit for shipment only after the FAT configuration is preserved. Record loose items, removed external equipment, transport braces, door locks, preservation, desiccants, fluid levels, battery isolation, protected interfaces, packing, lifting instructions and required arrival inspection.

Site acceptance testing (SAT) should take the FAT records as its starting point. It verifies damage-free arrival and the final interfaces: foundations or deck support, site power, earthing, utilities, external pipework, network communications, remote alarms, host fire and gas connections, environmental performance, noise and operator procedures.

The handover should explicitly state what the FAT proved, what SAT must prove, what remains open and who owns each action. That boundary protects both the buyer and supplier from using a factory test as evidence for an untested site condition.

Information the Buyer Should Provide with the RFQ

Approved technical specification, drawings, interface list and applicable standards or client requirements
Required FAT attendance, witness points, notice period, language, location and report format
Required functional scenarios, performance limits, alarm philosophy and cause-and-effect matrix
Electrical, HVAC, control, fire-and-gas, security and utility tests required at the factory
Required inspection records, certificates, calibration evidence, software backups and as-built documents
Transport configuration, lifting and preservation requirements and arrival-inspection expectations
Site conditions and interfaces that must be transferred to SAT
Punch-list classification, shipment-release authority and closure process

Procurement Takeaway

A FAT is a decision-quality record, not a showroom demonstration. It should prove that the manufactured package matches the agreed design and behaves correctly in the factory-testable operating scenarios, while making every site-dependent verification visible. TLS develops custom containerised solutions with structural, electrical, HVAC and controls interfaces coordinated around the project scope. Send the test requirements, drawings, cause-and-effect logic, witness plan and site-interface list to build a focused FAT and SAT sequence.

FAQ

What is the difference between FAT and SAT?

FAT verifies the package at the factory before shipment. SAT verifies the delivered package after installation and connection to the real site systems. FAT reduces site risk; SAT confirms the conditions that cannot be fully tested in the factory.

Should the customer attend the FAT?

Attendance depends on the project’s risk and contract. Even when the customer does not attend, the FAT plan, records, photographs where appropriate, deviations and signed report should provide traceable evidence. Critical witness points should be agreed before fabrication is complete.

Can a FAT prove transport or offshore suitability?

Only if the test scope specifically covers a defined handling or transport requirement and the relevant approval basis. A functional factory test alone does not prove a package is suitable for every road, marine or offshore lift or installation.

What should block shipment after a FAT?

Any unresolved issue that affects safety, required performance, legal or contractual compliance, transport readiness, protective functions or the ability to commission the package as agreed should be resolved or formally dispositioned by the authorized parties before shipment.