Prepare an MOC package.
From a P&ID revision to a complete management-of-change package with scope, impact, approval, and trace
What this covers.
Preparing a management of change, MOC package is the process safety engineering process of documenting every change to a covered facility per OSHA PSM 1910.119, l and the equivalent international regimes, UK COMAH, EU Seveso III, Canadian PSR. An MOC package carries the technical scope of the change, what tags, equipment, lines, and loops are affected, the safety and operability review, HAZOP node revisit, SIL impact, LOPA delta, the approval signatures from the affected disciplines, the training requirements for operators, and the cross-reference to the updated P&ID set. MOC discipline drives the audit trail. Missing MOC documentation is the most-cited deficiency in process safety audits.
Inputs.
- Pre-change P&ID set, baseline
- Post-change P&ID set, proposed
- Existing HAZOP study
- Existing SIL verification calculation
- Operating procedure for the affected node
Outputs.
- Tag-level change list with source-page references for every revised tag
- Updated I/O list reflecting the proposed change
- HAZOP impact assessment with affected nodes flagged
- SIL impact assessment with affected SIFs flagged
- Cross-discipline approval cover sheet
- Audit-traceable MOC package, PDF binder plus Excel workbook plus JSON for the MOC tool
MOC package contents by stage
| Stage | Source artifact | MOC document |
|---|---|---|
| Scope identification | P&ID revision diff | Tag-level change list with source-page references |
| Process safety review | HAZOP node walk | Re-rationalized HAZOP rows for the affected node |
| SIS impact assessment | SIL verification diff | Affected SIF list with revised PFDavg |
| Approval chain | Discipline lead signatures | Multi-discipline sign-off page |
| Operator training | Operating procedure update | Training record per operator |
| Trace plus closeout | Final P&ID plus updated I/O list | Cross-reference table for audit |
Step by step.
- 01Diff the pre-change and post-change P&IDRun the revision comparison. The tag-level diff becomes the technical scope of the change.
- 02Filter affected SIS scopeFilter the diff to SIS-classified tags. Any change touching a SIS tag triggers the SIF impact assessment.
- 03Re-walk affected HAZOP nodesCross-reference the changed tags against HAZOP node boundaries. Affected nodes get a revisit. Unaffected nodes carry forward.
- 04Update SIL verificationWhen the SIS architecture changes, sensor element added, voting reconfigured, final element replaced, the affected SIF runs through SIL re-verification.
- 05Assemble the discipline reviewEach affected discipline lead reviews the change scope and signs the approval page. The trace from the sign-off back to the tag-level diff is preserved.
- 06Archive in the MOC toolExcel workbook drops into Sphera ProcessMAP, Wolters Kluwer Enablon, ABS Group ABS Nautilus, or in-house MOC tooling. JSON export preserves the audit trail.
Common questions
What regulations drive MOC discipline.
Can the MOC package drive the HAZOP revisit automatically.
Related.
Start a workspace.
Upload the source documents, run the workflow, ship the document in the column shape the next consumer expects.