What Is Acceptance Testing? FAT, SAT, and Industrial Automation Explained.

What Is Acceptance Testing?

Acceptance testing is the process of verifying that a machine, robot, or automation system meets the requirements agreed upon between a supplier and its customer.

When a manufacturer purchases an automated production line, it needs more than a demonstration that the equipment can turn on and operate.

The system must perform its intended job at an acceptable level of quality, reliability, and safety.

Acceptance testing provides a structured way to evaluate those requirements before the customer formally accepts the equipment.

Key Takeaways

• Acceptance testing compares actual system performance against predefined requirements.
• Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT) are common stages in industrial automation projects.
• Clear, measurable acceptance criteria help reduce disputes between equipment suppliers and customers.

How Does Acceptance Testing Work?

Acceptance testing begins with a set of agreed performance requirements.

These may include production speed, positioning tolerances, payload capacity, functionality, and specified safety checks.

Consider a manufacturer purchasing a robotic palletizing system.

The supplier promises that the system will handle 20 boxes per minute using the customer's specified packaging.

An illustrative acceptance test might require the robot to demonstrate the agreed throughput over a defined operating period while meeting documented handling and quality requirements.

If the system fails to meet those requirements, the supplier and customer identify the necessary corrections before acceptance.

The exact tests and consequences of failure depend on the contract and application.

Factory Acceptance Test vs. Site Acceptance Test

Industrial automation projects commonly use two stages.

Factory Acceptance Test (FAT)

Performed at the supplier's facility before equipment is shipped. It checks that the system performs according to specified requirements under the test conditions available at the factory.

Site Acceptance Test (SAT)

Performed after installation at the customer's facility. It verifies the installed system against applicable requirements and helps identify issues associated with the installation environment.

Some projects also require Site Integration Testing to confirm that multiple connected systems work together correctly.

Why Is Acceptance Testing Important?

A robot that performs well in a supplier's workshop may behave differently after installation.

The customer's facility could have different lighting, production materials, utilities, network conditions, or surrounding equipment.

Acceptance testing helps uncover these issues before responsibility for the equipment formally changes hands.

It also creates a documented record of the system's condition and performance.

Frequently Asked Questions

Is acceptance testing the same as commissioning?

No. Commissioning involves preparing, configuring, and verifying equipment for operation. Acceptance testing determines whether specified requirements have been satisfied. The activities often overlap.

Does passing an acceptance test guarantee that a robot is safe?

No. Safety depends on the complete application, relevant standards, risk assessments, safeguards, and proper operation. Acceptance testing should include applicable safety requirements but does not replace them.

The Bottom Line

Acceptance testing helps manufacturers verify that automation equipment delivers the performance they purchased. Clear test criteria, documented results, and appropriate testing at both factory and installation stages make automation projects more predictable.