How to Build a Vendor Document Register for a Tower Packing Project

Tower packing procurement does not end when the supplier receives a purchase order.

For many EPC, chemical, refinery, and process-plant projects, the supplier must also submit a controlled set of technical and quality documents during engineering, manufacturing, inspection, and shipment.

If these documents are managed only through email attachments, projects can quickly lose control of:

• which documents are required;
• which revision is current;
• which documents are approved;
• which documents are still outstanding;
• which documents are required before manufacturing or shipment.

A Vendor Document Register, or VDR, solves this problem.

It provides a single controlled list of supplier documents and their required submission status.

1. What Is a Vendor Document Register?

A Vendor Document Register is a project document that identifies every supplier deliverable associated with the purchase order.

For a tower packing or tower internals package, the VDR may include:

• product datasheets;
• general arrangement drawings;
• fabrication drawings;
• material certificates;
• inspection procedures;
• ITP;
• dimensional inspection reports;
• PMI reports;
• COA;
• packing lists;
• certificates of conformity;
• final as-built drawings.

The exact list depends on project scope.

A small standard Pall Ring order may require only a few documents.

A custom structured packing and internals package may require dozens.

2. A VDR Is Not the Same as a Final Data Book

These two documents are related but serve different purposes.

The VDR controls document submission during the project.

The final data book collects the approved final records after manufacturing is complete.

Think of the workflow as:

VDR→ Document Submission→ Review→ Revision→ Final Approval→ Final Data Book

The VDR is therefore a live project-control tool.

The data book is a final project record.

3. Start With the Contractual Document Requirement

The first VDR should be built from:

• purchase order;
• technical specification;
• project document requirement;
• approved quotation;
• ITP requirements.

Do not simply copy another project's document list.

Different orders may require different levels of documentation.

For example:

A standard PP Pall Ring order may not require fabrication drawings.

A custom liquid distributor certainly may.

4. Give Every Document a Unique Reference

Each supplier document should have a controlled identity.

Useful fields may include:

• document number;
• document title;
• equipment tag;
• supplier reference;
• current revision.

Avoid filenames such as:

final drawing new.pdf

or:

updated packing drawing latest 2.pdf

These names are difficult to control.

A structured system might use:

PROJECT–EQUIPMENT–DOCUMENT TYPE–NUMBER

The exact coding system should follow project requirements.

5. Define When Each Document Is Required

Not every document is needed at the same stage.

A VDR may classify documents as required:

Before Manufacturing

Examples:

• approved datasheet;
• approved fabrication drawing;
• approved material specification.

During Production

Examples:

• material certificates;
• in-process inspection reports;
• PMI records.

Before Shipment

Examples:

• final inspection report;
• packing list;
• release note;
• certificate of conformity.

After Shipment / Final Handover

Examples:

• as-built drawings;
• final data book;
• complete quality dossier.

This timing prevents a critical document from being discovered too late.

6. Identify Documents That Block Manufacturing

Some documents are informational.

Others control whether manufacturing can begin.

For example:

A general product brochure should not normally stop production.

An unapproved custom structured packing fabrication drawing may.

The VDR should therefore indicate whether a document is:

• for information;
• for review;
• for approval;
• required before manufacturing;
• required before shipment.

This helps both supplier and buyer understand the consequence of delayed review.

7. Track Revision Status

A useful register may show:

Rev 0 — SubmittedRev 0 — Comments ReceivedRev 1 — ResubmittedRev 1 — Approved

This is far safer than searching an email chain to determine whether Revision 1 or Revision 2 is valid.

For geometry-sensitive products such as structured packing and tower internals, revision control directly affects fabrication risk.

8. Buyer Comments Should Be Closed Formally

Suppose the buyer comments:

Confirm sheet thickness.

The supplier should not only answer by email.

Where the comment affects the controlled document, the response should be incorporated into the revised submission.

Then the VDR should show that the revised document has been returned.

This creates a traceable closure.

9. Do Not Mix Commercial Documents and Technical Documents Without Logic

Some projects use one register for all deliverables.

Others separate:

• engineering documents;
• quality documents;
• commercial/shipping documents.

Either method can work.

The important point is that the project team knows where each required record is controlled.

10. Structured Packing Needs Stronger Drawing Control

A custom structured packing package may require documents such as:

• element arrangement drawing;
• segmentation drawing;
• layer identification drawing;
• support interface drawing;
• packing specification.

If tower diameter or manway dimensions change, the relevant drawing may require revision.

The VDR helps ensure that superseded versions are not treated as current.

11. Random Packing VDRs Can Be Simpler

Random packing normally requires fewer fabrication drawings.

A typical document set may include:

• product datasheet;
• material certificate or COA where applicable;
• inspection report;
• packing list;
• conformity certificate.

Do not create excessive documentation merely because a formal VDR exists.

Documentation should match product and project complexity.

12. Include Customer Review Time

Document control affects lead time.

If a drawing requires customer approval before fabrication, the schedule should account for:

Supplier preparation→ Submission→ Customer review→ Comment resolution→ Resubmission→ Approval

A quoted production lead time of 30 days should not automatically be interpreted as 30 days from PO if critical documents remain unapproved.

13. Track Outstanding Documents Before Shipment

Before shipment release, the register should be reviewed for open items.

For example:

Approved fabrication drawing — completeMaterial certificate — completeFinal inspection report — completeCertificate of conformity — missing

This makes the outstanding requirement visible before the cargo leaves.

14. Avoid Duplicate Documents Under Different Names

Projects sometimes request:

• certificate;
• quality certificate;
• conformity certificate;
• inspection certificate

without defining whether these are separate documents.

Clarify the purpose of each deliverable.

A VDR should reduce document duplication, not create it.

15. Suggested VDR Columns

A practical register may contain:

• Item No.;
• Document Number;
• Document Title;
• Equipment Tag;
• Supplier;
• Required Stage;
• Submission Date;
• Revision;
• Status;
• Customer Comment Date;
• Resubmission Date;
• Final Approval;
• Remarks.

For smaller projects, fewer columns may be enough.

Engineering Takeaway

A Vendor Document Register should answer:

What document is required?Who provides it?When is it required?What revision is current?Has it been reviewed?Does it block manufacturing or shipment?

For tower packing projects, the VDR creates a controlled bridge between:

Purchase Order → Engineering → Manufacturing → Inspection → Shipment → Final Records

It prevents critical technical information from becoming buried inside email threads.