Drawing revisions are the record of how a sheet changes over its life. Each revision gets a code, a date, a description and the initials of who made and checked it; clouds and revision triangles mark where on the sheet it changed; and transmittals record which revision was sent to whom and when.
At a glance
| Revision code | P01, P02… then C01 under ISO 19650 practice; A, B, C or 1, 2, 3 elsewhere |
| Revision table | Code, date, description, drawn and checked initials |
| Clouds and triangles | Where the sheet changed in this revision |
| Transmittal | Which revisions went to whom, when, for what purpose |
| Superseded sheets | Archived and marked, never left in circulation |
The parts of a revision record
| Part | Purpose |
|---|---|
| Code | Identifies the version uniquely |
| Date | When it was issued |
| Description | What changed, in words |
| Initials | Who made and checked the change |
| Cloud and triangle | Where on the sheet the change is |
| Status | What the revised sheet may be used for |
How revisions are used on projects
Under ISO 19650 practice, shared work carries preliminary revisions (P01, P02, with point versions such as P01.1 in work in progress), and published contractual information carries C revisions. The status and revision are metadata in the CDE and should be read onto the sheet from there. Every issue goes out with a transmittal, so the project can prove who had which revision on which date.
When a sheet is revised, the previous revision is superseded and archived. Site teams should remove superseded prints; disputes about "which drawing we built from" are settled by the transmittal record.
Older drawings record revisions more simply, sometimes as a line of initials and a date under the title block, with no description.
Variations
- Letter, number or ISO 19650 style codes, depending on the country and the client.
- Revision tables on the sheet, or the history kept only in the CDE.
- Construction-stage revisions for as-built or record drawings, often with their own codes.
Common mistakes
- Relying on clouds alone: changes are sometimes not clouded, and deletions leave nothing to cloud.
- Uploading a revision to the CDE without transmitting it to the people who need it.
- Building from preliminary revisions that were never issued for construction.
- Leaving superseded prints on site.
Where to read more
ISO 19650-2 and its national annexes for status and revision codes; national drawing and CAD standards for revision conventions; and the project's information standard and transmittal procedure.