FAT (Factory Acceptance Testing) and SAT (Site Acceptance Testing)
Commissioning a control system without first proving it works in a controlled setting is one of the costliest mistakes an industrial project can make. Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT) exist precisely to catch design errors, wiring mistakes, and logic flaws before they can cause downtime, safety incidents, or budget overruns once a system is live. Pro-Logic Technologies structures both stages as formal, documented processes for every automation project it delivers to Nairobi-area clients.
FAT takes place before equipment ever leaves the panel shop or integration facility. The control panels, PLC programs, HMI screens, and — where applicable — SCADA configurations are assembled and tested as a complete system in a simulated environment. Simulated or emulated field signals are used to exercise every input and output, confirming that sequences run correctly, interlocks trip when they should, alarms annunciate properly, and the HMI accurately reflects system state. This is deliberately the cheapest and least disruptive point at which to find a problem: a wiring error or logic bug caught at FAT costs a technician an afternoon, while the same error discovered during startup on a live production line can cost days of downtime and significant rework.
Pro-Logic Technologies runs FAT against a formal test plan developed jointly with the client during the design phase, covering every functional requirement — normal operation, abnormal conditions, failure modes, and safety interlocks. Client representatives are invited to witness testing directly, which serves two purposes: it builds confidence in the system before it ever reaches site, and it gives the client's own engineers early exposure to how the system behaves, which shortens the learning curve during actual startup. Every test point is signed off item by item, with any deviations logged, corrected, and retested rather than waved through.
SAT happens after installation, once the system is physically in place and connected to real field devices — actual valves, actual motors, actual instrumentation, actual process conditions. This stage validates what FAT cannot: that field wiring is correct, that instruments are calibrated and reading accurately, that actuators move in the right direction and within expected limits, and that the system performs correctly under genuine process conditions rather than simulated ones. SAT also confirms integration points that only exist on site — communication with other plant systems, power quality, grounding, and environmental conditions specific to the installation.
Because Kenyan industrial sites often involve retrofits into existing facilities rather than greenfield builds, SAT frequently surfaces site-specific realities that no amount of design-phase planning could fully anticipate — an existing cable run that limits routing options, a power supply with more noise than expected, or an instrument location that interferes with an existing structure. Pro-Logic Technologies builds contingency time into SAT schedules specifically to accommodate this kind of on-site problem-solving without derailing the overall project timeline.
Both FAT and SAT conclude with formal sign-off documentation, creating a clear record that the system was tested, verified, and accepted at each stage — documentation that matters not just for project closure but for warranty claims, insurance requirements, and future reference if a dispute over system performance ever arises. For regulated industries, this documentation can also form part of the compliance record required by auditors or certification bodies.
Skipping or rushing FAT and SAT to save time is a false economy that Pro-Logic Technologies actively discourages clients from pursuing, even under schedule pressure. The hours spent in structured testing consistently pay for themselves many times over by preventing the kind of startup chaos, safety near-misses, and reputational damage that come from commissioning an inadequately tested system on a live production floor.