In this guide 6 sections
When a drawing revises, update six things together: the control plan, the work instruction, the gauge or fixture, the inspection sheet, the PFMEA review note and the customer notification. Give each an owner and a sign-off date, and remove old copies from the floor before the first new part runs.
Read the revision before touching anything
Open the new drawing beside the old one. List what moved. A bore tolerance tightened, a surface finish callout appeared, or a note on burrs was added, and each change points to a different downstream document.
Check the effective date and the customer’s instruction. Some revisions apply from the next shipment, others from a given serial number or lot, and some need an approved deviation for stock already machined.
Record both revision letters on the job card. Do it before editing.
- Changed dimensions and tolerances
- New or removed special characteristics
- Changed material, heat treatment or coating notes
- Effective date and the customer’s letter or notice
Control plan and PFMEA
The control plan row for the changed characteristic needs a new specification, a check on the measurement method and a revised sample frequency if the risk moved. A tighter bore tolerance often shifts the check from a plug gauge to a bore gauge or a coordinate measuring machine.
Reopen the PFMEA line too. If the change adds a failure mode, such as a burr that now matters at an oil port, rate its severity and occurrence, then add the control.
Date the control plan revision. Name the drawing revision it answers to.
Work instruction, gauge and fixture
The operator holds the work instruction, not the control plan, so reissue it with the new dimension, the new tool offset and a sketch of the changed feature. Pull every old sheet from the machine and the supervisor’s drawer.
A gauge made to the old tolerance passes bad parts or fails good ones, so decide whether to modify it, replace it or retire it, and calibrate before use.
Check fixtures and cutting tool lists as well. A moved hole position can mean a new jig plate, a fresh drill bush and a changed offset in the CNC program.
- Work instruction reissued and old copies removed
- CNC program or setting sheet updated
- Gauge modified, replaced or retired with a calibration date
- Fixture or jig drawing revised
Inspection sheet, stock and customer notification
The incoming, in-process and final inspection sheets should show the new limits, because inspectors fill a familiar template by habit and copy the old numbers. Replace the sheet itself. A handwritten correction gets missed.
Decide what happens to stock. Parts at the old revision may ship, be reworked, be scrapped or wait for a customer deviation, so label each lot and segregate it in a marked bin.
Tell the customer what changed and when. Start any new PPAP submission now.
Close the loop with sign-off
One person, the process engineer, owns the revision change and collects every sign-off, and the first article after the change is measured against the new print. Keep that part as evidence.
Walk the floor that same day. Look at each machine, bench and inspection table that makes or checks the part, and pull any sheet that still carries the old revision letter.
File the checklist with the job. The next customer audit will ask for it.
Drawing revision change checklist
A checklist headed by part number, old revision, new revision and effective date, with six rows below: control plan, PFMEA, work instruction, gauge, inspection sheet, customer notice. Five columns record the owner, the change made, the old copy removed, the first-article result and the sign-off date, so no row closes without evidence.
Open a blank worksheet to printQuestions owners ask
Who should own a drawing revision change?
One named person owns it, usually the process engineer for that part, while quality, production and purchasing contribute and a single owner collects the sign-offs.
Do we need a new PPAP for every revision?
Not always. The customer’s manual says which changes require resubmission, so when in doubt ask them in writing and keep the reply filed with the job card.
What if parts at the old revision are already made?
Hold them and ask. The customer may accept the parts, ask for rework or require a deviation, and nobody should ship them on assumption before that reply arrives.
How do we stop old drawings staying on the floor?
Issue drawings only from a controlled source, mark printed copies with the issue date, and run a floor walk on the day the new revision goes live.