MOC checklist PDF.
The checks a P&ID revision passes before it reaches the field, gate by gate: drawings, tag delta, registers, SIS scope, cabling, software and sign-off.
- Drawing and document control4 checks, then initials and date
- Tag delta5 checks, then initials and date
- I/O list and instrument index4 checks, then initials and date
- SIS scope, per IEC 61511 and ISA 844 checks, then initials and date
- Cabling, marshalling and panels4 checks, then initials and date
- Software and integration4 checks, then initials and date
- Sign-off4 checks, then initials and date
Each gate is closed by the engineer who owns it. The MOC owner countersigns last.
The checklist, gate by gate.
Use it when a P&ID revision touches instrumentation, the I/O list, the instrument index or the SIS scope. Every box checked, every variance explained, then the MOC owner countersigns.
Drawing and document control
- Latest controlled P&ID revision identified and stamped
- Markup or redline source documented and dated
- Drawing legend matches the house standard and ISA 5.1 edition
- Off-page connectors traced across every affected page
Initials and date
Tag delta
- Added tags listed, each with its signal class
- Removed tags listed with their disposition, delete or retire
- Renamed tags listed with the old to new map
- Loop numbers verified unique
- Safety instrumented tags, as the SRS and cause and effect matrix name them, split into their own change list
Initials and date
I/O list and instrument index
- I/O list updated to the new tag set
- Instrument index updated, mechanical-only tags included
- PLC card sizing re-checked against the spare-capacity rule
- Cabinet count re-checked for terminal density
Initials and date
SIS scope, per IEC 61511 and ISA 84
- SIS tags reviewed for SIL allocation impact
- Safety requirements specification updated for added or changed SIFs
- Proof-test schedule updated
- Bypass and override conditions documented
Initials and date
Cabling, marshalling and panels
- Cable schedule updated for added and removed instruments
- Marshalling cabinet impact assessed
- Hazardous-area classification verified for new field locations
- Intrinsic safety barrier scope updated where it applies
Initials and date
Software and integration
- PLC tag table regenerated and imported
- DCS and HMI graphic changes scoped
- Alarm thresholds reviewed for added trip points
- Historian point list updated
Initials and date
Sign-off
- I&C engineer review
- Process safety review, HAZOP or LOPA where it applies
- Operations review
- MOC owner countersign
Initials and date
Common questions
When does a P&ID revision need an MOC.
Whenever the revision changes what is installed or how it is controlled: tags added, removed or renamed, a loop rescoped, a trip moved into or out of the safety system, or a panel and cabling change. A drafting correction that changes nothing physical is a document-control matter, not a change.
What does the tag delta gate cover.
Additions, removals, renames, and any split that moves a tag into or out of the safety system prefix. Those four are where a revision quietly breaks the I/O list, the instrument index, and every downstream count built from them.
Who signs it.
Each gate is signed by the engineer who owns that scope, instrumentation and controls, process safety, and operations. The MOC owner countersigns once every box is checked, which is what makes the sheet an audit record rather than a to-do list.
We run it on your drawings.
The page is a reference you read at the drawing table. From your drawing set the register comes back built, each row traceable to the sheet it came from.