FAT vs SAT: What Each Stage Must Prove

Why this matters in food manufacturing Factory Acceptance Testing proves as much as reasonably possible before shipment. Site Acceptance Testing proves the installed system works safely and effectively in the real factory environment. Treating SAT as a repeat FAT wastes time; treating FAT as optional pushes supplier defects into the production installation window. 1. What FAT should prove Verify build against specification, functional sequences, controls, alarms, guarding, safety functions, documentation, hygienic design and maintainability. Use representative loads or simulation where real product is unavailable. Record what cannot be tested until site. Those items become explicit SAT requirements rather than assumptions. 2. What SAT should prove Confirm installation, utilities, interfaces, production rates, product handling, cleaning, changeovers, reject systems, data connections and performance under real operating conditions. SAT should also confirm actions from FAT are closed or formally transferred with owners. 3. Define acceptance criteria early Write measurable pass criteria into the project before the tests. Throughput, yield, temperature, accuracy, changeover time, uptime demonstration and safety performance should not be negotiated after the equipment arrives. Where performance depends on product or upstream…