Reconcile an as-built P&ID.
From the IFC drawing set to the as-built drawing set, surfacing every revised tag, loop, and equipment item
What this covers.
Reconciling an as-built P&ID is the engineering process of comparing the issued-for-construction, IFC drawing set to the as-built drawing set produced after construction is complete, surfacing every tag added, dropped, moved, or revised over the construction phase. The reconciliation produces a change report scoped to the affected disciplines, I&C, mechanical, electrical, piping, feeds the MOC documentation, updates the master I/O list and equipment list to the as-built state, and produces the closeout package the owner receives.
Inputs.
- IFC drawing set
- As-built drawing set
- Master I/O list, legacy baseline
- Master equipment list, legacy baseline
Outputs.
- Change report scoped per discipline, I&C, mechanical, electrical, piping
- Updated master I/O list reflecting as-built state
- Updated master equipment list reflecting as-built state
- MOC documentation per change
- Owner closeout package. As-built drawing set plus as-built documents plus change report
What surfaces in the as-built reconciliation
| Change type | Detection | Downstream impact |
|---|---|---|
| Tag added on drawing | New row in extraction | Added to I/O list plus cable schedule |
| Tag dropped from drawing | Missing from extraction | Removed from I/O list plus JB schedule |
| Tag renamed | Loop-context match | Cross-reference table to legacy tag |
| Equipment service change | Service column diff | Datasheet revision triggered |
| Loop number reassignment | Loop-consistency pass | Loop folder index rebuild |
| Pipe-class break moved | Line list diff | Stress reanalysis flag |
Step by step.
- 01Establish the IFC baselineExtract the IFC drawing set as a baseline workspace. The IFC I/O list, equipment list, and line list become the comparison anchor.
- 02Extract the as-builtUpload the as-built drawing set as a revision workspace. Page-by-page extraction produces the as-built document set.
- 03Run the revision diffSide-by-side comparison surfaces every added, dropped, moved, and revised tag with a per-row source reference. Drift between the IFC and the as-built becomes data.
- 04Generate per-discipline change reportFilter the diff by discipline so I&C, mechanical, electrical, piping each receive a slice. Owner-facing change report rolls the slices up.
- 05Update master registersApprove the as-built delta to update the master I/O list, equipment list, and line list to the as-built state. The legacy baseline archives.
- 06Ship the closeout packageBundle the as-built drawing set, the as-built documents, and the change report into the owner handover package.
Common questions
Does this work when the IFC and as-built sets carry different drawing numbering.
What if the as-built is a mix of CAD-exported and scanned redline pages.
Can the change report drive the MOC documentation directly.
Related.
Start a workspace.
Upload the source documents, run the workflow, ship the document in the column shape the next consumer expects.