Why Factory Acceptance Test (FAT) Becomes a Battle Between Buyers and Suppliers: Managing Risks in Custom Automation Equipment Projects

Introduction: FAT Is Not Just a Machine Test, It Is a Risk Management Process

For many companies purchasing custom automation equipment, the Factory Acceptance Test (FAT) is often considered a simple technical checkpoint before shipment.

The assumption is straightforward:

The machine runs.

The functions work.

The supplier completes the test.

The equipment is shipped.

However, real industrial projects are rarely that simple.

In complex automation projects, FAT is often the stage where technical expectations, contractual responsibilities, payment milestones, and delivery risks come together. Many disputes between buyers and suppliers do not happen because the equipment completely fails. Instead, they occur because both parties have different interpretations of what “successful acceptance” actually means.

For international companies sourcing automation equipment from China, FAT represents the final opportunity to identify technical and commercial risks before the equipment leaves the factory.

A well-managed FAT does more than verify machine operation.

It confirms that:

• Technical requirements are clearly defined;

• Acceptance criteria are measurable;

• Engineering changes are controlled;

• Performance data is documented;

• Delivery responsibilities are understood.

Therefore, Factory Acceptance Test is not simply an equipment inspection. It is a structured industrial risk management process.

Why FAT Becomes a Negotiation Between Buyers and Suppliers

1. Technical Specification: Are Both Parties Using the Same Standard?

The foundation of any successful FAT is a clear and controlled Technical Specification.

The commercial contract defines business terms, but the Technical Specification defines how the equipment will be evaluated.

Typical requirements include:

• Production capacity;

• Cycle time;

• Product quality requirements;

• Equipment functions;

• Safety requirements;

• Inspection accuracy;

• Software functions;

• Reliability expectations.

However, custom automation projects naturally evolve.

During months of development, customers may request:

• New product requirements;

• Process improvements;

• Additional inspection functions;

• Software modifications;

• Mechanical adjustments.

The problem is not change itself.

The problem is uncontrolled change.

A common scenario occurs when a customer verbally requests additional performance improvements, but the change is never formally documented.

For example:

The original specification requires a 12-second cycle time.

Later, the customer expects a 10-second cycle time after production optimization.

The supplier completes FAT based on the approved specification, while the customer evaluates performance based on the latest expectation.

Both sides believe they are correct.

The result is a commercial dispute.

Professional automation projects therefore require strict document control principles. Technical specifications should have:

• Clear revision history;

• Formal approval;

• Defined acceptance criteria;

• Traceable engineering changes.

A FAT without a common technical baseline creates unnecessary risk.

2. Engineering Changes: Who Owns the Additional Risk?

Engineering changes are unavoidable in custom automation equipment projects.

New products require new tooling.

Production processes are optimized.

Customer requirements evolve.

The key question is:

Who is responsible for the impact of the change?

Without a formal Engineering Change process, buyers and suppliers often have different expectations.

The buyer may believe:

“This is part of the original project.”

The supplier may believe:

“This requires additional engineering effort.”

A professional Engineering Change process should evaluate:

• Technical impact;

• Cost impact;

• Schedule impact;

• Safety impact;

• Validation requirements.

Only after formal confirmation should the revised requirement become part of the FAT acceptance criteria.

Verbal agreements may accelerate short-term communication, but they often create long-term project risks.

3. Machine Running Does Not Mean Machine Is Ready

One of the most common FAT misunderstandings is assuming that a machine passes acceptance simply because it can operate.

Industrial customers do not purchase machine movement.

They purchase stable production capability.

A professional FAT should verify:

• Functional performance;

• Production stability;

• Repeatability;

• Alarm response;

• Safety functions;

• Recovery procedures;

• Continuous operation capability.

In many factories, FAT verification includes:

• Continuous production runs of several hours;

• Hundreds or thousands of production cycles depending on the application;

• Cycle time measurement;

• Alarm history review;

• Quality data recording;

• Test result documentation.

For example, an automation line may require:

• 8-hour continuous operation;

• 500–1,000 production cycles;

• Verification of critical sensors and actuators;

• Review of abnormal stop records.

Relevant industrial practices may reference internationally recognized frameworks such as:

• ISO 9001 principles for document control and process management;

• ISO 12100 principles for machinery risk assessment;

• IEC 60204-1 requirements related to electrical equipment of machinery.

These standards do not replace FAT procedures, but they support a disciplined approach to industrial risk reduction.

The purpose of FAT is not to prove that equipment can run once.

The purpose is to demonstrate that equipment can reliably perform under defined production conditions.

4. Payment Milestones and Shipment Risk

Another major area of conflict occurs between FAT approval and equipment shipment.

Most automation equipment contracts define a sequence:

• Complete FAT;

• Obtain acceptance approval;

• Receive milestone payment;

• Release equipment for shipment.

However, production urgency often creates pressure.

Customers want faster delivery.

Suppliers want payment protection.

When suppliers ship equipment before receiving FAT milestone payments, commercial risk increases significantly.

Once equipment leaves the factory, the supplier loses part of its negotiation advantage.

FAT issues may later become mixed with:

• Installation problems;

• SAT issues;

• Operator training;

• Production optimization;

• Warranty discussions.

The original payment milestone can become delayed by unrelated topics.

For international equipment projects, especially when purchasing from a China factory, maintaining clear FAT acceptance and shipment procedures is critical for reducing delivery risk.

Industrial Best Practices for FAT Risk Control

A mature FAT process normally includes:

FAT Protocol

A predefined testing procedure describing:

• Test sequence;

• Acceptance criteria;

• Measurement methods;

• Responsibilities;

• Documentation requirements.

FAT Checklist

A structured checklist covering:

• Mechanical functions;

• Electrical systems;

• Software functions;

• Safety systems;

• Production performance.

Objective Evidence

Successful FAT should generate:

• Test records;

• Performance data;

• Alarm logs;

• Non-conformance reports;

• Corrective action records.

The key principle is simple:

If acceptance cannot be measured, acceptance cannot be managed.

Industrial Case Study: When Early Shipment Created Two Years of Payment Risk

A manufacturer developed a customized production line for a customer facing urgent capacity requirements.

The customer requested immediate shipment after FAT and promised to complete payment shortly afterward.

To support the relationship and production schedule, the supplier shipped the equipment before receiving the FAT milestone payment.

The equipment was installed and successfully entered production.

However, when the supplier requested payment, the customer introduced additional requirements:

• Software improvements;

• Process adjustments;

• Interface modifications;

• Additional optimization requests.

Some requests were reasonable improvements.

Others exceeded the original project scope.

Because many discussions had not been formally documented, both parties disagreed about responsibility.

The supplier continued supporting the customer, but payment was delayed for nearly two years.

The main failure was not equipment performance.

The failure was inadequate risk management.

The project lacked:

• Clear change control;

• Written responsibility boundaries;

• Strict FAT payment management.

The lesson is clear:

Trust is important, but industrial projects require documented processes.

Three Common FAT Mistakes

Mistake 1: Buyers Expect Unlimited Supplier Responsibility

Equipment suppliers are responsible for delivering according to agreed requirements.

Additional improvements and new functions should follow formal change procedures.

Clear boundaries protect both parties.

Mistake 2: Suppliers Assume Operation Equals Acceptance

A machine that runs successfully may still have reliability risks.

Stable production requires measurable verification.

Mistake 3: Using SAT to Solve FAT Problems

SAT should confirm installation and production integration.

It should not become a replacement for incomplete FAT verification.

Solving problems before shipment is usually faster and less expensive.

Where Independent Industrial Risk Consultants Add Value

Complex automation projects involve different stakeholders with different priorities.

Suppliers focus on engineering execution, manufacturing efficiency, and contractual delivery.

Buyers focus on production reliability, investment protection, and long-term operational performance.

Because of these different perspectives, hidden risks may remain unnoticed until equipment reaches the production site.

An Independent Industrial Risk Consultant provides objective technical assessment without participating in equipment manufacturing or equipment sales.

Typical support includes:

• Technical Specification Review;

• Supplier Capability Assessment;

• Engineering Change Risk Review;

• Factory Acceptance Test (FAT) Witness;

• Manufacturing Readiness Assessment;

• Delivery Risk Evaluation;

• Site Acceptance Risk Review.

For international companies sourcing custom automation equipment from China, independent technical verification helps establish a common understanding between buyers and suppliers before equipment shipment.

The goal is not to replace suppliers or project teams.

The goal is to identify risks earlier, improve transparency, and reduce costly disputes.

Conclusion: Risk Management Starts Before Equipment Leaves the Factory

Factory Acceptance Test is not the end of an automation project.

It is one of the most important risk control points before equipment enters real production.

Successful FAT depends on more than machine performance.

It requires:

• Clear technical requirements;

• Controlled engineering changes;

• Objective testing methods;

• Documented evidence;

• Defined commercial responsibilities.

As automation systems become more complex and global equipment sourcing continues to grow, companies increasingly recognize the value of independent technical risk assessment.

The earlier industrial risks are identified, the lower the potential cost of failure.

Industrial risk cannot always be eliminated, but it can be identified, controlled, and managed before it becomes a production problem.

About the Author

The author is an Independent Industrial Risk Consultant specializing in Factory Acceptance Testing (FAT), supplier capability assessment, technical risk review, and delivery risk management for custom automation equipment manufactured in China.

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