The Revision Control System Minimum Requirements
Every project needs:
- A revision register — a log of every drawing, its current revision letter/number, and all prior revisions
- Revision clouds — graphical markups on the drawing showing exactly what changed from the prior revision
- A revision description — a written note in the title block describing what changed (not just 'per EOR comments')
- Distribution control — a system that ensures new revisions replace old ones in all active locations
- CNC file synchronization — a protocol that requires NC files to be re-issued with every drawing revision that affects holes, cuts, or profiles
Revision Clouds and Their Importance
Revision clouds are the fastest way for a shop foreman, inspector, or EOR to identify what changed between revisions. Without clouds, every receiver of a revised drawing must compare it against the prior revision line by line — a time-consuming process that often gets skipped under pressure. Good revision clouds circle exactly what changed; bad revision clouds cloud the entire drawing (which communicates nothing) or are absent entirely.
Controlling Distribution of Revised Drawings
The most dangerous moment in revision control is the gap between when a new revision is issued and when the old revision is physically removed from active use on the shop floor. Create a physical and digital handoff protocol: when Rev B of a drawing is issued, Rev A is collected from all active binders, stamped 'Superseded — Do Not Use,' and archived. On digital systems, revision locking prevents the old revision from being opened without a warning flag. Confirm receipt of new revisions from the shop floor supervisor — not just confirmation that the file was emailed.