MDB vs MRB vs VDB

Ask a Norwegian EPC, a Texan fabricator and a Dutch vessel shop for "the book" and you will hear three different names for the same thing. The documentation package that proves an item was built, tested and inspected to specification grew up independently in several code regimes — ASME, PED, NORSOK, company specs — and each regime named it in its own image.

That would be harmless trivia, except that the names end up in contracts. Purchase orders ask for an "MRB per SDRL", a "vendor data book in three volumes", a "final documentation package" or a "dossier constructeur" — and quality teams burn hours working out whether these are different deliverables. Spoiler: they almost never are. This article maps every common term to what it actually means, so you can read any spec and know exactly what to compile.

Item-centric books (MDB, MRB, MDR, QC data book, quality dossier) document how one item was made. Supplier-centric books (VDB) document everything the buyer needs about the delivered equipment — which includes the item-centric book as a part.

The Manufacturing Data Book is the compiled, indexed set of quality records for a fabricated item: material certificates to EN 10204, welding qualifications (WPS, PQR, WPQ), NDT reports, pressure and functional test reports, dimensional reports, coating records and the certificate of conformity — organised against an agreed index. If you want the full anatomy, the pillar guide to Manufacturing Data Books walks through every chapter.

"MDB" is the most common label in North-Sea and continental European projects, and in specs written under NORSOK influence. It emphasises data: the book is the structured data set that lets an owner trace every pressure-retaining part back to a heat number and every weld to a qualified welder.

The Manufacturing Record Book is the same deliverable with an Anglo-American accent. Oil & gas operators, ASME shops and most EPC specification libraries say MRB; the checklists, chapter structures and review workflow are interchangeable with the MDB. Our chapter-by-chapter MRB checklist applies verbatim to a book labelled MDB — only the cover page changes.

One nuance worth knowing: because "record" suggests evidence after the fact, some projects treat the MRB as strictly the as-built quality records, while "data book" scopes may pull in a few engineering documents too. When a spec matters, the index agreed at kick-off — not the acronym — defines the content.

The Vendor Data Book changes perspective. It is not defined by the item but by the commercial relationship: an equipment supplier (pump, valve, exchanger, compressor, instrumentation) delivering to an EPC or owner compiles a VDB covering the whole supply — general arrangement and detail drawings, datasheets, calculations, the QC data book / MRB for fabricated parts, installation-operation-maintenance manuals, preservation instructions and spare parts lists.

Its table of contents is dictated by the project's Vendor Document Requirements list (VDR, also SDRL — Supplier Document/Data Requirements List), which assigns document codes, review classes and due dates. That is why the same vendor ships differently-structured books to different EPCs — each project imposes its own VDR. The Vendor Data Book guide for equipment suppliers covers how to run that multi-EPC reality from one document library.

Around the three main acronyms orbits a cloud of adjacent labels. MDR is the trickiest because it is two things: in NORSOK Z-001 it is the Manufacturing Data Record — the formal name for the compiled book — while in ASME Section VIII the Manufacturer's Data Report is a specific signed code form (the U-1A and friends) that gets filed inside the book.

Quality dossier is the generic European name, at home in PED 2014/68/EU and ISO 9001 contexts — French projects say dossier constructeur, and the quality dossier guide maps it to the ISO clauses. You will also meet final documentation, handover package, turnover package (TOP) and as-built dossier — construction-side names that widen the scope to commissioning records, but keep the same skeleton of certificates, test reports and traceability.

Use the client's term. The book is a contractual deliverable, and mirroring the purchase order's language avoids review friction: if the PO says MRB, title the book MRB. Where you set the standard yourself, a practical rule of thumb:

• Fabricating an item (vessel, spool, skid, structure) → MDB or MRB, per your market's habit.
• Supplying catalogue or engineered equipment to an EPC → VDB, structured against the project VDR/SDRL.
• NORSOK scope → MDR per Z-001, with the index the standard prescribes.
• PED / CE marking context → quality dossier (or technical documentation, for the CE file itself).

Whatever the label, agree the index before fabrication starts. Every experienced document controller has a story about a book rejected at handover because the index was assumed rather than agreed.

Here is the practical good news: because every variant is built from the same records, one well-organised structure serves them all. Material certificates, welding records, NDT, tests, dimensional control, coating, sub-supplier documents, certificates — collected once, compiled per whichever index the contract demands. That is the premise behind our free MDB / MRB template (a 12-chapter index that adapts to any of the names above), and behind the six-step MDB workflow if you are setting up the process from scratch.