Which Drawing Revision Did Your Supplier Actually Price?

Before comparing prices or placing an order, ask the supplier to identify the drawings behind its quotation, sheet by sheet. Record the drawing numbers, revisions, issue dates, specifications, and clarifications it used. Then compare that list with the package you intended it to price.

A quotation dated after a drawing update may still use an earlier takeoff. An email confirming receipt of new files tells you they arrived; you still need confirmation that their contents are reflected in the offer. Keep fabrication authorization separately identifiable under the project's agreed procedures.

In an April 2025 construction-management discussion, a participant reported receiving weekly drawing changes after estimating and contracting, then struggling to keep site teams aligned. The procurement question starts earlier: which version was included in the price?

Make the quotation name its document basis

Give the supplier a dated document schedule with the quotation request. Ask it to return that schedule with its offer, confirming the documents used and listing any exceptions.

Include:

• Drawing number, title, revision, and issue date for every relevant sheet
• Specification title, edition or revision, and applicable addenda
• Relevant requests for information (RFIs), responses, sketches, and clarification references
• Model identifier and version when a model forms part of the pricing information
• Package or transmittal reference linking the list to the files actually issued

Ask the supplier to identify documents it could not open, conflicting information, and assumptions made where details were missing. Preserve its response alongside the quotation. If the offer says only “as per drawings,” request the missing schedule before treating its technical scope as confirmed.

This approach borrows a useful principle from NASA's configuration-management guidance: uniquely identify the information under control, establish a documented baseline, and retain the history of changes. NASA's process serves its own engineering programs; a buyer can apply the underlying discipline through a modest document register.

Track individual sheets rather than a folder label

A drawing package can legitimately contain sheets at different revisions. In an illustrative set, a layout might remain at Revision A while a connection sheet advances to Revision C. Renaming the folder “Rev C” would hide that distinction.

Compare each sheet's title block with the issue schedule. Check for omitted sheets, duplicates, additions, and withdrawals. If two files carry the same drawing number and revision but show different information, ask the issuer to resolve the identity conflict. A later download timestamp does not resolve it.

Use the blank register below. Give the register itself a reference and issue date, and retain the version returned with each quotation.

Project / package: ______ Register reference / date: ______

Supplier: ______ Quotation reference / date: ______

Copy the issuer's purpose accurately, such as pricing, coordination, or construction. Keep the recorded issue purpose distinct from the supplier's pricing response. Where drawings and models coexist, identify the project's agreed controlling information and refer discrepancies to the responsible technical party.

For structural-steel projects, AISC 303-22, Section 3.6 is a specific reference on identifying drawing revisions and communicating model changes. Apply the edition and provisions relevant to your contract, together with AISC's applicable errata. Use the register as a purchasing aid; the project contract and responsible professionals determine the applicable requirements.

Describe what changed in purchasing terms

Revision clouds help a reader find changes, but the buyer also needs to connect each change to the purchase. Ask the responsible technical reviewer to identify affected components, quantities, materials, finishes, connection details, and interfaces with other packages.

Give each change a reference and link it to the drawing sheet and any related RFI. Record whether it affects a quotation line, a purchase-order line, or an item that was previously absent. Describe the affected feature precisely enough for the supplier to review it without guessing.

Use this blank change record once per affected sheet or linked group of sheets:

• Change reference and drawing number: ______
• Previous revision → issued revision: ______
• Changed feature and location on sheet: ______
• Affected component, quantity, and quotation or PO line: ______
• Related specification, RFI, or interface reference: ______
• Technical reviewer and unresolved question: ______

An overlay can help locate differences. It cannot settle an unclear design instruction or establish whether a supplier priced the revised requirement. Keep unresolved questions visible until the appropriate person answers them.

Obtain a response that closes the pricing gap

Ask for separate confirmation of receipt and pricing treatment. A supplier may have received the complete package while still assessing its impact, or it may have updated only part of its offer.

Use a response record linked to the change reference:

Use explicit response descriptions: included in the stated offer, no impact confirmed, revised offer attached, or assessment pending. Leave an unanswered impact as pending. Do not enter zero because the supplier has not replied.

For a replacement quotation, record which earlier offer it supersedes and whether replacement covers the whole package or specified lines. Retain both versions. Before using the revised total in a comparison, check that its document schedule matches the intended pricing package and that earlier exclusions have been resolved or carried forward explicitly.

Keep the priced set and the released set retrievable

Store an unaltered snapshot of the documents supporting each accepted quotation. Give the active fabrication set a clearly identified location and status, with release authority recorded through the project's agreed process. Restrict changes to controlled records to the people responsible for issuing them.

Record fabrication authorization separately: status ______; authorized scope ______; authority and date ______; authorization record link ______.

Keep superseded files available for history while removing them from normal working selections. Update active links and address downloaded or printed copies through the project's document-control process. Replacing a shared file alone leaves uncertainty about what another team is using.

Before ordering, run a simple retrieval test:

• Can a colleague open the exact sheets supporting the selected price?
• Does the supplier's acknowledgment identify those same revisions?
• Are unresolved changes and excluded requirements visible?
• Can the team separately identify the documents authorized for fabrication and the basis for that authorization?

If the answers differ between purchasing, engineering, and the supplier, resolve the mismatch before treating the price baseline as settled.

Need help establishing a clear quotation basis? Contact SourceRating with your drawing schedule, specifications, destination, and quotations. If you have not selected suppliers yet, share the project requirements and document status so the initial sourcing request can start from a defined scope.