Bid engineering guide

VDRL and MDR: what equipment vendors must deliver, and what to check at bid stage

A plain-English guide to the vendor data requirements list and the final manufacturing data record, for bid engineers, proposal engineers and project managers at equipment manufacturers.

By Ademola Afolabi, Founder, New Odyssey Ltd · Last reviewed: 2026-10-23

The short answer

A vendor data requirements list (VDRL) sets out every document an equipment vendor must deliver, when, and whether the buyer reviews it. The manufacturing data record (MDR), or data book, is the final dossier of quality records. Both are scope you price, so check them at bid stage.

Key Takeaways

VDRL, SDRL and VDR are company names for the same kind of list; read the tender's own definition.
Each line has a document, a due date and a review requirement.
Documents you cannot supply, or cannot supply on time, are deviations to declare in the offer.
The MDR, or data book, collects the records the ITP produces; start it during manufacture.

What a VDRL is, and what it is called

A vendor data requirements list is issued by the EPC contractor or owner with the material requisition. It lists the documents the vendor must deliver for the order, each with a due date and a review requirement. Companies use different names for it, such as supplier document requirements list (SDRL) or vendor document register (VDR). For the short definition, see the VDRL glossary entry.

Typical VDRL columns (own summary; layouts vary by company)
Column	What it holds
Document code or title	The document type, such as general arrangement drawing, datasheet, ITP or data book
Timing	When it is due: with the bid, weeks after order, before manufacture, before test or before shipment
Purpose	For review or approval, or for information only
Format and copies	PDF, native files, number of copies and language, where the project sets them

Review codes and returns

After award, the buyer returns each document submitted for review with a status code. Typical meanings are accepted, accepted with comments, rejected and resubmit, or for information. Many codes also say whether work may go ahead. Each project's document procedure defines its own codes, so read the legend rather than assuming.

The MDR or final data book

The manufacturing data record, also called a manufacturing record book, data book or final documentation dossier, holds the quality records for the equipment as built. It usually includes material certificates, test and inspection reports, the signed inspection and test plan, calibration records and certificates of conformity. The buyer often sets its index. It is usually one of the last items on the VDRL.

What to check at bid stage

Read every VDRL line and mark which documents you produce as standard and which are extra work.
Check each due date against your design and production schedule.
Check numbering, format, language and copy requirements; renumbering to a project scheme takes time.
Confirm that sub-suppliers can provide documents for bought-out items.
Give each document a row in your compliance matrix, and move any you cannot meet to the technical deviation list.

OdysseyGPT reads the document requirements in the tender package with the rest of the specification. Each becomes a requirement with a status, such as document requested, and a quote with the page, sheet or cell. It does not generate the VDRL or manage submittals after award. See OdysseyGPT for manufacturing.

Buyer questions

20 questions bid engineers, proposal engineers and buyers ask. Last reviewed: 2026-10-23

What is a VDRL in engineering procurement?

A VDRL, or vendor data requirements list, lists every document an equipment vendor must deliver for an order. For each document it gives a due date and says whether the buyer needs it for review or only for information. It is issued with, or referenced by, the material requisition, so it is part of the scope of supply.

Are VDRL, SDRL and VDR the same thing?

They usually mean the same kind of list. Names vary by company: vendor data requirements list (VDRL), supplier document requirements list (SDRL), vendor document register or schedule (VDR) and others. Some companies separate the requirement list from the vendor's own register of documents. Read the definition in the tender rather than assuming one meaning.

What is an MDR, or manufacturing data record?

An MDR is the final dossier of quality records for the equipment as built. It is also called a manufacturing record book, data book or final documentation dossier, depending on the company. It typically holds material certificates, test reports, inspection records, the signed ITP and certificates of conformity. It is usually one of the last items on the VDRL.

Who issues the VDRL?

The EPC contractor or owner issues it, as part of or alongside the material requisition. The vendor responds with its own document list or register, numbered and dated to match. On large projects the EPC's document control team manages submissions and returns them with review comments.

What documents are usually on a VDRL?

Common items include general arrangement drawings, datasheets, calculations, the inspection and test plan, test procedures, material certificates, weld and NDE records, painting procedures, installation and maintenance manuals, spare parts lists and the final data book. The exact list depends on the equipment and the owner's standards, so read each line.

How are VDRL due dates set?

Due dates are often counted in weeks from the purchase order, or tied to events such as before manufacture, before testing or before shipment. Some documents are due with the bid. Check that each date is achievable for your design and production schedule, and declare any you cannot meet in the offer.

What do review codes on returned vendor documents mean?

The buyer returns each submitted document with a review code. Typical meanings are accepted, accepted with comments, rejected and resubmit, or for information only. Many codes also say whether work may go ahead. The codes and their exact meaning differ by company, so check the legend in the project's document procedure.

What is the difference between 'for review' and 'for information' documents?

A document for review, or for approval, must be returned by the buyer with a code before you rely on it, and may hold up work. A document for information is sent for the buyer's records and is not formally approved. Knowing which is which helps you plan the schedule around review cycles.

Do I have to use the buyer's document numbers?

Often, yes. Many projects ask vendors to number documents to the project's own scheme, and to submit them with a transmittal. Some accept the vendor's number with the project number alongside. Check the project's document procedure at bid stage, because renumbering every drawing and record is real work that should be priced.

Why should I check the VDRL at bid stage?

Because documents are part of the scope you are pricing. A calculation you do not normally produce, a manual in another language, native file formats or extra copies all cost time and money. Documents you cannot supply, or cannot supply on time, are deviations that belong in your technical deviation list.

What are common VDRL deviations in equipment tenders?

Common ones include design calculations the manufacturer treats as proprietary, documents asked for earlier than the design allows, editable native files instead of PDF, specific languages and documents for bought-out items the vendor does not own. Each can be raised as a deviation or clarification, with a proposed alternative such as a summary instead of a full calculation.

How does the VDRL link to the ITP?

The inspection and test plan is usually one of the documents on the VDRL, often due for review before manufacture. The records the ITP produces, such as test reports and signed inspection sheets, then feed into the final data book. Check both together, so the tests and records you promise line up.

What goes into a final data book?

A final data book usually holds material certificates for pressure parts, test and inspection reports, NDE and weld records where relevant, the signed ITP, calibration records, certificates of conformity and approved deviations or concessions. The required index is often set by the buyer. Ask for it early, so records are collected during manufacture, not after.

Can late documents delay payment?

Often, yes. Many purchase orders tie a payment milestone to the final documentation, or hold a retention until the data book is accepted. Late or rejected documents can also delay inspection release and shipment. Read the payment terms alongside the VDRL, and plan the document schedule as part of the project, not after it.

Am I responsible for sub-supplier documents on the VDRL?

Usually, yes. The vendor on the purchase order is responsible for documents covering the whole scope, including bought-out items such as actuators, motors and instruments. Check early that your sub-suppliers can provide the certificates, drawings and manuals the VDRL asks for, in the format required.

Is there a standard VDRL format?

There is no single format used everywhere. Most owners and EPCs use their own. Some industry specifications, such as the IOGP JIP33 set, pair each equipment specification with a separate document setting out the information the supplier must provide. Always use the format the tender asks for.

Should VDRL items appear in my compliance matrix?

Yes. Treat each required document as a requirement with a status, just like a material or test. That makes it easy to see which documents you can supply as asked and which need a deviation or clarification. See the engineering compliance matrix guide for the columns to use.

What are common VDRL mistakes after award?

Common mistakes include submitting documents late, using the wrong numbering or title block, sending a revision without marking what changed, and missing the buyer's comments when resubmitting. Another is starting the data book only at the end. A simple register that tracks each document, revision and review code avoids most of these.

How does OdysseyGPT handle VDRL requirements in a tender?

OdysseyGPT reads the document requirements in the tender package along with the rest of the specification. Each one becomes a requirement with a status, such as complies, deviates or document requested, and a quote with the page, sheet or cell. You export them in the compliance matrix and deviations and clarifications list for your engineers to review.

Does OdysseyGPT manage vendor document submittals after award?

No. OdysseyGPT works at bid stage, checking requirements against your documents. It does not generate the VDRL, track submittals, assign review codes or send documents to the customer. Document control after award is usually handled in dedicated document-control systems or the buyer's own portal.

Frequently asked questions

Is the VDRL part of the contract?

Usually yes. It is issued with or referenced by the material requisition, so the documents on it are part of the scope of supply on the purchase order.

When is the MDR delivered?

Usually at or after shipment, once all records are complete. Some orders tie a payment milestone to its acceptance.

References

What is vendor documentation

Project Materials

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IOGP JIP33 standardized equipment specifications

IOGP