What is a Factory Acceptance Test and Why Do You Need One?

If you’ve been told that you don’t need to do a factory acceptance test, you may be missing out on a great opportunity. Here’s what you need to know.

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What is a Factory Acceptance Test (FAT)?

A Factory Acceptance Test (FAT) is a series of tests performed on equipment and systems prior to installation at the customer’s site. It involves functional testing of the system, as well as testing of the system’s hardware and software. These tests are done to verify that the equipment meets the specified requirements and functions as intended.

FATs are typically conducted at the manufacturer’s site but can also be conducted at the customer’s site if necessary. It aims to identify any potential problems with the equipment or system before it is installed so that these problems can be addressed before the equipment is put into service.


The purpose of FATs is to ensure that the system meets all of the specified requirements and is ready for final installation and operational testing.

The FAT is an essential step in the process of commissioning a new factory or industrial plant. This test is used to ensure that the equipment and systems in the factory meet the required specifications and standards. It is usually performed by the manufacturer of the equipment, but it can also be done by an independent third party.

The FAT is important because it helps ensure that the equipment in the factory will work properly and safely. This test can also help identify any potential problems with the equipment or systems before they are put into operation.


There are many benefits of factory acceptance testing, including:

  • Allowing the customer to see the equipment in action
  • Ensuring that the equipment meets the customer’s needs
  • Identifying any problems with the equipment before it is installed at the customer’s site
  • Avoiding costly mistakes and delays
  • Reducing the risk of unexpected problems or issues

The main benefits of FAT testing are that it offers peace of mind to the buyer that the equipment will meet their expectations and allows any issues to be identified and rectified before the equipment is delivered. This can save considerable amounts of time and money, as correcting problems after delivery can be much more costly and difficult.

3 Factory Acceptance Test Protocols

The test protocols for a FAT must be carefully planned and documented to ensure that all relevant aspects of the system are tested.

Below are the three test protocols to follow to have a successful test:

1. Planning

The first stage of a Factory Acceptance Test protocol is planning by establishing what needs to be tested and how it will be tested. The manufacturer, specifically the Original Equipment Manufacturer (OEM), outlines the initial scope of the FAT during the customer’s bidding phase.

The plan, which encompasses all applicable customer specifications, standards, and drawings, is written to help establish the acceptability and credibility of the equipment being supplied. By communicating the scope of the FAT to the customer at the outset, all expectations and requirements can be met.

2. Documentation

Next is documentation, wherein a set of reference documents will be compiled as reference. Some of these documents include:

  • Applicable codes or references
  • Checklists and procedures specific to the FAT
  • Calibrations and certifications as required by contract
  • Customer scope and specifications
  • Drawings (General Arrangement, Piping & Instrumentation Diagram, etc.)
  • Datasheets
  • Inspection Test Plan (ITP)

These documents are then reviewed by the manufacturer or OEM to check if the supplied equipment meets the designs required by the customer prior to the FAT.

3. Testing

This is where the testing proper happens, in which the following must be achieved:

  • Follow and connect the ITP and FAT procedure
  • Take, record, and submit raw data to the customer
  • Review the drawings and designs together with the customer or representative
  • Review the Non-Destructive Examination (NDE), coating, and storage procedures

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The 6 Stages of the Acceptance Test

There are different names, styles, and formats for acceptance tests, but in the end, the term “Final Acceptance” is meant to achieve one specific goal—a validation that the system works how, when, and where it was designed.

Below are the stages that must be taken to achieve the Final Acceptance:

  • Stage 1: Factory Acceptance Test – Also known as “box testing,” this test is performed on each piece of equipment or system at the location of the manufacturer where it’s built.
  • Stage 2: Customer Acceptance Test – CAT showcases the system’s features, how it functions, and failure scenarios in a controlled environment.
  • Stage 3: Site Acceptance Test – Also called “Power Up” or “Cold Start” tests, these tests prove that all equipment at one site powers up and works as anticipated.
  • Stage 4: Coverage Verification Test – CVT records and evaluates actual Radio Frequency (RF) transmission performance against the area performance and coverage guarantees specified in the system design and agreed upon in the contract.
  • Stage 5: Final System Acceptance Test – This test is carried out to demonstrate system features, functions, and failure scenarios in the system’s final configuration.
  • Stage 6: Burn In Period – Also known as the “14-day” or “30-day” test, it is the start of the timeframe during which customers can use the equipment and identify any problems.

How Do You Write a Factory Acceptance Test?

The FAT procedure depends on the design specifications and intended function of the machine that should undergo the testing. Even when each step of the factory acceptance testing varies per equipment, project engineers can adhere to the following standard FAT procedure:

Communicate with the client

Upon the client’s arrival at the factory floor, the manufacturer or supplier should discuss the details that have yet to be addressed before the acceptance testing. Clarifying project adjustments such as change orders shows an understanding of the client’s production process and the ability to deliver on their expectations.

Review the detailed test plan

A test plan is a tool used to clearly illustrate the timing and sequence of tests or inspections based on the equipment’s purchase order specifications and functional requirements. When walking through the test plan with the client, specify the reference documents, or the basis for the acceptance criteria, such as construction codes and verifying documents, or the proof of test or inspection results, such as certificates.

Perform safety risk assessments

Project managers should identify and eliminate hazards in the test area before commencing the acceptance testing. Complete the safety inspection with a mobile device and ensure that machinery nameplates are visible, emergency stop buttons are accessible, and safety switches are installed. Use a mobile-ready factory acceptance test checklist to verify if pre-tests were conducted, corrective actions were implemented, and all FAT personnel are equipped with the appropriate PPE.

Demonstrate equipment performance

Confirm the FAT protocol and proceed with the functional and regulatory tests—from the startup process to the maintenance procedure. As the quality team proves the performance of the custom-built machine, the client will ask questions to gauge how it will perform when installed in their facility. Ad hoc tests may be required when nonconformity is revealed.

Apply additional customization

When the punch list has been resolved and additional customization has been applied to the equipment, an official statement of acceptance should be signed by the manufacturer or supplier’s quality manager, head design engineer, and fabrication manager and the client’s representative, head operator, and maintenance coordinator.

The client will eventually perform a site acceptance test (SAT) upon proper installation at the permanent operation position. The SAT further verifies equipment performance in relation with other systems at the site.

Tips to Effectively Implement a Factory Acceptance Test

So how do you go about effectively implementing a FAT? Here are a few tips:

  • Make sure that you have a clear and concise plan for the test. This should include all of the objectives that you want to achieve.
  • Work with the factory to ensure they understand the requirements for the test.
  • Make sure you have enough people on your team to perform the test.
  • Allow adequate time for the test to be performed.
  • Finally, use a Factory Acceptance Test (FAT) checklist to keep your projects on track and within their budget.


FAQs about Factory Acceptance Tests

All the engineers tasked with the equipment should participate in the testing when the FAT is conducted.

Depending on the complexity or number of the equipment, a factory acceptance test may take about two days or two weeks to be completed.

To prepare for the factory acceptance test, you will need to gather your documentation and have it ready to present to the testing team. This includes your requirements specification, design documents, test plans, and other relevant information. You should also be prepared to answer any questions that the testing team may have.

A factory acceptance test is a test of equipment carried out at the manufacturer’s premises. Meanwhile, a site acceptance test is a test of equipment carried out at the customer’s premises.

SafetyCulture Content Team
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SafetyCulture Content Team

SafetyCulture Content Team
The SafetyCulture content team is dedicated to providing high-quality, easy-to-understand information to help readers understand complex topics and improve workplace safety and quality. Our team of writers have extensive experience at producing articles for different fields such as safety, quality, health, and compliance.