Executive summary
Sequence commissioning system by system — utilities before process, individual equipment before integrated lines — and define Factory Acceptance Test and Site Acceptance Test protocols with quantified acceptance criteria at the time equipment is ordered, not once it arrives. Protect the commissioning window as a fixed schedule element rather than a buffer absorbed by construction delay.
Factory Acceptance Testing at the vendor's facility catches defects before shipment, when correction is materially cheaper than after installation; skipping FAT to save schedule time typically shifts cost, not removes it.
Why projects fail without this
- Commissioning window treated as flexible buffer absorbing construction delay
- FAT protocols not defined until equipment is ready to ship
- No system-by-system commissioning sequence, only a single 'commissioning phase' on the schedule
- Utilities commissioning not completed before process equipment commissioning begins
- Vendor commissioning support contracted late, creating availability risk
- Acceptance criteria not quantified before testing begins
How disciplined teams run it
Factory Acceptance Testing
Tested at the vendor's facility before shipment, against acceptance criteria agreed at order placement.
Site Acceptance Testing
Re-verification after installation, confirming the equipment performs as tested at FAT under site conditions.
System-by-system sequencing
Utilities, then individual equipment, then integrated lines — not a single undifferentiated commissioning phase.
Vendor commissioning support
Contracted and scheduled well in advance to avoid availability conflicts across multiple concurrent projects.
Punch-list management
Formal categorisation of outstanding items by whether they block start-up, distinguishing critical from cosmetic.
Comparison table
| Stage | Scope | Gate before proceeding |
|---|---|---|
| FAT | Equipment tested at vendor site | Acceptance criteria met and signed |
| Installation and pre-commissioning | Static checks, loop checks | Punch-list critical items closed |
| SAT / utilities commissioning | Utilities live, individual equipment energised | Utility capacity confirmed |
| Integrated / process commissioning | Full line running under load | Performance validation criteria met |
Commissioning sequence and gating
Risks and governance considerations
- Acceptance criteria agreed only at the point of testing, rather than at order placement, invite dispute when equipment underperforms
- Commissioning compressed by upstream construction delay tends to produce rushed start-ups with unresolved punch-list items carried into operation
- Utilities commissioned after process equipment risk masking process performance issues caused by inadequate utility supply
- Vendor commissioning engineers are often shared across multiple client projects; scheduling conflicts should be identified and contracted against early
What to prepare
- FAT and SAT protocols with quantified acceptance criteria, agreed at order placement
- System-by-system commissioning sequence integrated into the master schedule
- Vendor commissioning support contracted and scheduled in advance
- Punch-list categorisation protocol distinguishing critical from non-critical items
- Utilities commissioning plan completed before process equipment commissioning starts
What to measure
Frequently asked questions
Is FAT necessary if the vendor has a strong track record?
Track record reduces risk but does not eliminate the value of verifying the specific unit ordered performs to the agreed criteria before it is shipped and installed.
What should happen to open punch-list items at start-up?
Only non-critical items should remain open; critical items — anything affecting safety, product quality or equipment protection — should be closed before start-up proceeds.
How far in advance should vendor commissioning support be contracted?
Typically several months, particularly for specialised equipment where the vendor's commissioning engineers are shared across concurrent projects globally.
Related investment and financing knowledge
Project Delivery Intelligence
Quality Assurance
Project Delivery Intelligence
Performance Validation
Project Lifecycle Stage
Commissioning
CAPEX Intelligence
Technology Investment
CAPEX Intelligence
Factory Modernization
Project Delivery Intelligence
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Global B2B Group does not sell equipment and does not represent lenders, export credit agencies or development banks. This material is published to help industrial organisations plan, structure and prepare capital projects. It is general information for decision-making, not financial, legal or tax advice.