By Dovydas Kersys · Chapter 4 of 58 in Machine Commissioning.
Before you begin: Follow the machine documentation, risk assessment, site procedures and lockout/tagout requirements. Commissioning can expose personnel to electrical energy, stored pressure and unexpected motion. Never defeat a safety function merely to make a test easier. Examples and diagrams are generic and must be checked against the actual machine.
Commissioning creates the final technical truth of a machine. Installation changes, terminal swaps, field reroutes, spare I/O use and software modifications must be captured while they are still fresh.
Commissioning documentation should converge toward one controlled as-built set.
Why this matters during commissioning
Maintenance depends on accurate drawings and backups long after the startup team leaves. An undocumented “small fix” can cost hours during the first production breakdown.
Commissioning procedure
- Start with a controlled revision of electrical, pneumatic, hydraulic, layout and network drawings.
- Mark site redlines as changes are made.
- Verify wire numbers, terminal numbers, device tags and PLC addresses against the physical installation.
- Update drawings to as-built status only after verification.
- Archive final source files, exported PDFs and software projects together.
Common failure patterns
- Technicians using different drawing revisions.
- Handwritten redlines that disappear after startup.
- PLC tag changes without drawing changes.
- Spare field wires repurposed without documentation.
Evidence to record
- Drawing revision used for testing
- Redline reference
- Person making change
- Date and reason
- Final as-built verification
FIELD RULE: If the physical machine and the drawing disagree, neither should be assumed correct until the discrepancy is resolved.
Continue the series
- Previous chapter: FAT, SAT and Acceptance Criteria: Commissioning Guide
- Next chapter: Punch Lists and Change Control: Commissioning Guide
- Browse all Machine Commissioning chapters
Adapted from Machine Commissioning for Maintenance and Automation Technicians, by Dovydas Kersys. © 2026 Dovydas Kersys. Featured cover image is an AI-generated editorial illustration.