Greenfield Factory Commissioning: A Complete FAT/SAT and Startup Guide

Commissioning success is determined by planning quality — not testing speed. Pre-commissioning defines every test procedure, acceptance criterion, responsibility assignment, and documentation requirement before a single system is energized. The Commissioning and Qualification (CQV) plan must be adjusted based on reliance on third parties, vendor expertise, regulatory requirements, and the interplay between FAT, SAT, and IQ/OQ/PQ.

Virtual commissioning tests the actual PLC code and robot programs against a physics-accurate digital twin before equipment arrives on-site. Research shows this can save up to 75% of commissioning time. The virtual model responds to PLC outputs and generates sensor inputs exactly as the physical system would — every interlock, sequence, and safety check is tested against real control logic. Projects that include virtual commissioning consistently achieve 3-5% cycle time accuracy on the first physical run.

FAT is the quality gate between build and delivery — performed at the vendor's facility to verify that equipment meets design, functional, and compliance requirements before shipping. It is not a demo; it is an execution of approved protocols with pass/fail criteria, controlled deviations, and signed results. Identifying issues at the vendor's site costs a fraction of resolving them on-site. FAT also provides the opportunity for the owner's team to train alongside the vendor's expert teams — knowledge transfer that is critical for long-term commissioning success.

SAT verifies that equipment delivered and installed at your site functions correctly in the actual operating environment — which differs from the vendor's facility in temperature, humidity, utility supply, vibration, and electromagnetic interference. SAT re-confirms critical FAT results and adds site-specific tests: utility connections, network integration, interface verification with adjacent systems, and environmental performance. A passed FAT does not guarantee a flawless installation — transport damage, utility gaps, and site-specific conditions can introduce new issues.

Integration testing verifies that all equipment, control systems, and software platforms work together as a unified production system — not just individually. Field devices must be correctly reflected on dashboards and controllable from central locations. MES, ERP, CMMS, SCADA, and AI platforms must receive and process data correctly through the Unified Namespace. This is the stage where system-level issues surface: communication timing, data format mismatches, handshake failures, and network bottlenecks.

For regulated industries (pharma, food, medical devices), production qualification follows IQ/OQ/PQ protocols. For non-regulated manufacturing, this stage validates that production output consistently meets quality targets, dimensional tolerances, and customer specifications at progressively increasing volumes. FAT and SAT documentation can be leveraged to support IQ and OQ — avoiding unnecessary repetition and compressing the qualification timeline.

Handover transitions the facility from "project mode" to "operations mode." This is not a single event — it's a structured transfer of ownership covering documentation, training, maintenance systems, and operational procedures. The digital twin transitions from a commissioning tool to a living operational asset. CMMS shifts from configuration to active maintenance management. The project team's knowledge must be formally captured and transferred to the operations team.