What Is a Factory Acceptance Test? FAT Explained for Industrial Automation.

What Is a Factory Acceptance Test?

A Factory Acceptance Test, or FAT, is a structured evaluation of equipment performed at the supplier's facility before it is shipped or installed at the customer's site.

Its purpose is to verify that specified functions and requirements have been satisfied under the conditions available during factory testing.

FATs are common in industrial automation projects involving robots, production machinery, control systems, and integrated equipment.

For example, a manufacturer purchasing a robotic packaging machine may attend a FAT to observe the system operating before authorizing shipment.

Key Takeaways

• FATs evaluate equipment at the supplier's facility before delivery.
• Tests are performed against agreed requirements and acceptance criteria.
• A successful FAT reduces certain project risks but does not replace testing after installation.

How Does a Factory Acceptance Test Work?

Imagine a company purchasing a robotic palletizing system.

The supplier completes assembly and internal testing at its own facility.

The customer and supplier then conduct the agreed FAT.

The test might require the system to demonstrate specific operating sequences, handle representative boxes, and exchange signals with the intended control equipment.

The team records the results and identifies any requirements that have not been met.

If problems are discovered, the supplier can address them before the system is shipped.

The exact acceptance conditions and consequences of failed tests depend on the project agreement.

What Is Typically Checked During a FAT?

Common activities include:

Functional testing: Verify that the equipment performs its intended operations.

Performance testing: Measure agreed quantities such as cycle time or throughput.

Control-system testing: Confirm software sequences, interfaces, and operating modes.

Safety-related verification: Check applicable protective functions and documented requirements.

Documentation review: Confirm that specified manuals, drawings, and other deliverables are available.

Some projects also include operator demonstrations or training.

Not every FAT can reproduce the final operating conditions.

FAT vs. SAT

A Factory Acceptance Test occurs at the supplier's facility.

A Site Acceptance Test, or SAT, occurs after installation at the customer's location.

FAT can identify problems before shipment.

SAT helps verify the installed system under actual site conditions.

For example, a robotic cell may pass its FAT but experience communication or material-handling problems after being integrated with existing factory equipment.

Those issues may only become apparent during site testing.

FAT vs. Commissioning

Commissioning is the broader process of preparing and verifying equipment for operation.

FAT is a defined testing stage typically performed before delivery.

A project may include FAT, installation, commissioning, and SAT as separate but connected activities.

Frequently Asked Questions

Does passing a FAT guarantee that equipment will work after installation?

No. Transportation, installation, utility connections, and site integration can introduce additional issues.

Does the customer have to attend the FAT in person?

Not always. Depending on the agreement, testing may involve remote participation, recorded evidence, or third-party representatives.

The Bottom Line

Factory Acceptance Testing helps customers verify important equipment requirements before delivery. It can identify problems early and reduce installation risk, but successful deployment still requires appropriate site testing and commissioning.