factory acceptance test

**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.