A full batch, beautifully made, to revision C
The parts pass inspection against the drawing in the job folder. They are packed, the C of C is signed and they go out. Two days later the customer's goods in rejects the lot, because the order said revision D. The bore moved, or a chamfer was added, or the material changed. Revision D was emailed to sales a month ago and never made it to the shop floor.
Now there is a remake to fit in, material to reorder and a conversation about who pays.
Where the revision gets lost
Most shops do have a drawing folder. The trouble is that there are copies everywhere else too: in the estimator's quote folder, printed in the job pack, saved on the CAM workstation, taped to a machine, and in the customer's portal. When a new issue arrives, some of those copies get updated and some do not.
- The revision on the purchase order is not compared against the drawing on file when the order is entered.
- Repeat orders are run from the old job pack without checking for a newer issue.
- CAM programs are named by part number only, not by revision.
- Printed drawings are not withdrawn when a new issue comes in.
- Engineering changes arrive as an email with a marked up PDF, not a formal new revision.
What each wrong revision costs
The obvious cost is the scrapped batch and the machine time to make it again. Behind that is the late delivery on the remake, the time spent on the nonconformance report, and a black mark on your supplier rating with that customer. For work going into regulated sectors, the customer may also want to know how it happened and what you have changed.
Revision control we build around your orders
- A drawing register holds every customer drawing with its part number, revision, date received and status: current, superseded or awaiting review.
- When a purchase order arrives, the part number and revision on each line are read and compared with the register. A mismatch, or a revision you have never seen, is flagged before the job is created.
- Each job is locked to one drawing revision. The job pack, the inspection plan and the traveller all pull from that single file.
- New revisions trigger a check list of what else needs updating: CAM program, setup sheet, fixture, inspection plan, open jobs and open quotes.
- On the shop floor, a tablet or screen at each cell shows the drawing for the job by scanning the traveller, so the setter is not relying on a printed copy.
- Superseded revisions stay on record for traceability but are clearly marked and cannot be attached to a new job.
| Moment | What the register checks |
|---|---|
| Order received | PO revision matches the current drawing |
| Repeat order | Whether a newer issue has arrived since last time |
| New revision received | Open jobs, quotes and programs affected |
| Job set up | Setter sees the locked revision only |
| Final inspection | Report references the same revision |
What the shop floor gets
The setter scans the job and sees one drawing, the right one. The office sees at order entry that the customer has quoted a revision you do not have, and can ask for it before any metal is cut. When a new issue lands, someone is prompted to check whether the program and the fixture still fit, rather than finding out at first off.
You also end up with a clean history of which revision every past job was made to, which is what a customer audit tends to ask for.
Is revision control your weak spot?
- Printed drawings live at the machines.
- CAM files are named without a revision.
- You have had a batch rejected for being made to an old issue.
- Repeat orders are run straight from the last job pack.
- Engineering changes arrive as marked up PDFs in someone's inbox.