Do I need to issue a new revision for a typo fix?

Yes. Any edit to a signed, in-use WPS creates a new revision. The old revision stays on file. This is a controlled-document discipline borrowed from ISO 9001 and AISC certification programs.

How do I number revisions?

Most shops use Revision 0 for the original release, then Revision 1, 2, 3… for each edit. Some use date-based revisions (Rev 2026-05-11). Pick a scheme and apply it consistently across the library.

Does a new revision need a new signature?

Yes. The CWI, welding engineer, or QC manager re-signs and re-dates each revision. The signature line on the older revision is preserved in the archive.

How long do I keep old revisions?

Minimum five years, or longer if your contract / AHJ / certification body requires it. AISC-certified shops should keep them for the life of the certification.

WPS revision control: when to issue a new revision (and how to do it right)

A WPS is a controlled document. Edits create new revisions, with full audit trail. Here's the standard for revision control that survives a third-party audit.

A Welding Procedure Specification is a controlled document. That has practical consequences: any change creates a new revision, the old revision stays on file, and the revision history is auditable. Shops that nail revision control breeze through AISC and third-party audits; shops that don't lose findings on every visit.

When to issue a new revision

Any of the following triggers a new WPS revision:

A change to any documented value (amperage range, voltage range, preheat, etc.)
A change to the joint sketch or detail callout
An addition or removal of a position, thickness range, or base metal
A change in the supporting PQR reference
A change to the filler metal classification or diameter
A typo correction, even cosmetic
An update to the code edition citation (e.g., D1.1:2020 → D1.1:2025)

A few non-triggers (use judgment, document the reasoning):

Reformatting a printed copy without changing content
Adding the WPS to a different binder or folder

Numbering schemes

Two common schemes:

Integer revisions — Rev 0 (release), Rev 1, Rev 2… This is the most common scheme and works well when changes are infrequent.
Date-based revisions — Rev 2026-05-11. Useful when changes are frequent or when revision number alone is ambiguous.

A third option, less common but useful for large shops, is alphanumeric — Rev A.1, A.2, B.1. Major revisions bump the letter, minor edits bump the number.

Pick one scheme. Apply it consistently. Don't mix.

The minimum revision history block

Every WPS should carry an in-document revision history table:

Rev	Date	Author	Change summary	Approved by
0	2026-01-15	Sarah Kim, CWI	Initial release	Sarah Kim, CWI
1	2026-03-04	Sarah Kim, CWI	Added 3G position	Sarah Kim, CWI
2	2026-05-11	Joe Tran, QC Mgr	Updated to D1.1:2025	Sarah Kim, CWI

This block is the single most useful artifact an auditor can read.

Storage and archive

Three storage rules that survive audits:

Single source of truth. One location stores the live WPS library. Welders don't pull WPSs off a desktop or a USB stick.
Old revisions don't disappear. They move to an archive folder, not the trash. They stay readable and named so anyone can pull "Rev 0 of WPS-25-007" five years later.
Welder access is read-only. The CWI, welding engineer, or QC manager is the only role that can edit and re-sign. Welders pull the current revision; they don't edit.

Modern WPS software enforces this automatically. Word + a network drive can do it too, but the discipline has to be enforced by process.

The most common audit finding

In our experience: a welder is pulling Rev 1 from a printed binder on the floor, but Rev 2 was issued last month and never reached the floor. Production work is being made to a superseded procedure. That single finding has failed AISC audits.

The fix: a printed-copy control log, or — more reliably — a software-driven library where the floor terminal always shows the current revision.