Mechanical Completion
Certificate (Excel)

A Mechanical Completion Certificate (MCC, or MC certificate) is the formal handover document that transfers a system or subsystem from the construction contractor to the commissioning team. It certifies that all mechanical, piping, electrical, instrumentation, and civil scope on the system is installed per the approved AS-built drawings, that all inspection and test records (ITRs) are closed, that hydrotest, NDE, calibration, and loop check are complete, that Punch List A items are closed, that Punch List B items are formally transferred to the commissioning team, and that the system is ready for pre-commissioning. The certificate is signed by the construction lead and accepted by the commissioning lead.

Required columns: certificate number (typically MCC-XXXX), system / subsystem identifier and description, plant / unit / area, system boundary reference (P&ID and sheets), equipment tag list per system, construction contractor, issuing discipline, scope of work reference, approved AS-built P&IDs and isometrics, ITR index per discipline, hydrotest pack reference and closeout, NDE acceptance, welder qualification, cleanliness and reinstatement sign off, box-up punch closeout, calibration certificates, loop check records, electrical continuity and IR tests, vendor FAT certificate index, Punch List A items closed (per ASME PCC-2 closeout reference), Punch List B items transferred, and sign-off blocks for construction, commissioning, and witness. See the CFIHOS handover reference.

Pathnovo, an engineering document intelligence platform, builds the MC certificate package by consolidating the system tag list from the AS-built P&IDs, indexing all ITRs and certificates per equipment tag, cross-checking the punch list register for open A items per system, and assembling the dossier per the CFIHOS handover taxonomy. The platform flags missing certificates (e.g., a tag has no hydrotest record, no calibration certificate, or no FAT) before the certificate is issued. Drafts are reviewed by the construction and commissioning leads. See the engineering handover workflow and AS-built documentation workflow.

Mechanical Completion is the construction-to-commissioning handover: the system is built, tested, and ready for pre-commissioning, but not yet operating. Pre-commissioning, then commissioning, then performance test, then final acceptance follow in sequence. Final Acceptance (also called Provisional Acceptance Certificate or PAC) is the owner-to-EPC handover at end of warranty and after the performance test demonstrates the plant meets the contracted performance guarantees. The MC certificate is signed during construction; Final Acceptance is signed months to years later. The two are separate documents with different acceptance criteria and different signatories.

Punch List A items are 'must close before MC' items: anything that prevents safe energisation or hydrotest pressurisation (missing valve, wrong gasket, incomplete weld). Punch List B items are 'can carry forward to commissioning' items: cosmetic painting, signage, insulation cosmetic finish, minor structural touch-ups. The MC certificate confirms all A items are closed and lists all B items with a target closeout date during commissioning. Per ASME PCC-2 (Repair of Pressure Equipment and Piping) practice, A items must have full QA closeout records before the construction contractor can transfer the system. See the system turnover package template.

CFIHOS (Capital Facilities Information Handover Specification) defines the data taxonomy and class library for project information handover between owners and contractors. The MC certificate aligns with CFIHOS by tagging every certificate, ITR, drawing, and AS-built reference to a CFIHOS class (equipment class, document class, document type code). The MC dossier becomes a structured CFIHOS deliverable rather than a folder of PDFs, which allows direct upload to the owner's plant information system at handover. See the CFIHOS handover checklist template.

On a brownfield revamp, the MC certificate covers only the revamp scope: new and modified systems, not existing untouched systems. The system boundary on the P&ID must be precisely demarcated so the construction contractor's MC scope is unambiguous (the tie-in flange typically defines the boundary). On Indian PSU refinery turnarounds, MC sign off includes statutory acceptance from the local boiler inspector for IBR-registered equipment (per the IBR compliance reference) and from PESO (per the PESO compliance reference) for hazardous service piping. The MC certificate references the statutory sign offs as separate attachments.