When to use: Tracking Factory Acceptance Testing (FAT — logic and HMI verified at the integrator's shop, before shipment) and Site Acceptance Testing (SAT — physical wiring and full-system integration verified on-site) for a PLC/SCADA control system. Click each item to cycle Pending → Pass → Fail.
Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT) are the two commissioning gates every PLC/SCADA control system passes through before going live. FAT verifies logic, HMI, and panel wiring at the integrator's shop, where a defect is a program edit; SAT verifies the same system against real field devices, real cabling, and real process conditions on-site, where a defect can mean a field re-wire. This tracker separates the two phases so nothing gets tested at the wrong stage.
FAT uses simulated or forced I/O on the bench — there is no real product, no real sensors, no real plant-floor electrical noise. It is the cheapest place to catch a logic error, an interlock that doesn't fire, or a mismatched I/O point, because fixing any of those at the shop is a program edit or a panel correction, not a field trip. SAT happens after the panels are installed and wired to real field devices — it tests exactly the things FAT structurally cannot: sensor alignment against real product variation, network performance under real electrical noise, and whether the full system holds together running at production speed.
A failed FAT item is nearly always cheaper to fix than the same failure found at SAT — a forced-I/O logic test that fails at the shop means editing the PLC program before it ever ships. The same failure, if missed at FAT and only caught in the field, can mean diagnosing it through real wiring, real cable runs, and reduced access — often under schedule pressure with the line already staged for startup. That cost asymmetry is the core reason FAT exists as a distinct, mandatory gate rather than skipping straight to on-site testing.
FAT (Factory Acceptance Testing) verifies PLC logic, HMI functionality, and panel wiring integrity at the integrator's shop using simulated/forced I/O, before the system ships. SAT (Site Acceptance Testing) verifies the same system on-site with real field devices, real wiring, and real process conditions, culminating in a full-system integration run at production speed.
No — FAT cannot test anything that requires real field devices, real cable runs, or real process/product variation. Sensor alignment, network performance under actual plant-floor electrical noise, and full-system integration at production speed are only provable on-site, regardless of how thoroughly FAT was executed.
FAT is commonly witnessed by the end client or their engineering representative at the system integrator's shop before shipment. SAT is typically witnessed by the same client representative, plant operations staff, and often the integrator's commissioning team, on-site as the system goes live.
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