Factory acceptance test is the pre-shipment verification performed at the vendor site to confirm tool functionality against purchase specifications - it identifies issues early when correction is faster and less costly than field rework.

What Is Factory acceptance test?

• Definition: FAT phase that validates installation-ready tool performance in the supplier factory environment.
• Test Scope: Mechanical operation, control logic, subsystem checks, safety interlocks, and baseline process indicators.
• Participation Model: Vendor executes tests with customer witnessing or joint execution depending on contract.
• Output Artifacts: FAT protocol, deviations, corrective actions, and shipment release recommendation.

Why Factory acceptance test Matters

• Early Defect Removal: Catching issues before shipment avoids expensive teardown and schedule impact on site.
• Commissioning Speed: Better FAT quality reduces SAT troubleshooting and accelerates qualification.
• Contract Confidence: Provides objective evidence that purchased capability exists before delivery acceptance.
• Supply Chain Efficiency: Prevents shipping and installing tools that still need major redesign work.
• Project Risk Reduction: FAT readiness is a critical predictor of successful startup timelines.

How It Is Used in Practice

• Protocol Freeze: Lock FAT test plan, limits, and witness requirements before build completion.
• Deviation Handling: Classify failures by severity and require closure or approved concession prior to shipment.
• Data Preservation: Archive FAT baselines for later SAT comparison and root-cause references.

Factory acceptance test is a high-leverage pre-delivery quality gate for capital equipment programs - strong FAT execution materially improves startup reliability and reduces downstream commissioning risk.