FAT failures discovered on site cost multiples of FAT failures in a bench lab. TECHNLOGIX PTY LTD writes FAT scripts from the same requirements document used for quoting—traceable IDs, pass/fail, witness signatures.
Who must attend
Maintenance, operations, and quality should witness scenarios they will live with—not only project managers. If someone cannot attend, delegate authority to accept deviations explicitly.
What belongs in FAT
Sequences, alarms, safety interlocks, integration handshakes, and recovery from comms loss. Cosmetic HMI tweaks can wait; incorrect jam logic cannot.
Evidence pack
Export logic versions, IO forcing logs, screen recordings of fault injection, and signed checklist. Store with the asset in your document system—not in an integrator’s inbox.
Summary
Skipping FAT to save a week on the schedule is how you lose a weekend on the floor. We price FAT honestly and defend it when clients feel schedule pressure.