Rank the options, strongest first: remove the possibility, error proof it, detect it, then train or remind. Match an action to each cause: the occurrence, the escape and the system gap. Give every action an owner and a date, and write the reaction plan as steps. Training and reminders are support, never the root cause fix.
Thursday, week 16. The action meeting. The last meeting like this ended with a list that began with the word retrain. Today the list starts somewhere else.
You have a proven cause, a proven escape and a system gap. Each needs the strongest action available. Rank them, strongest first:
- Remove the possibility. Change the design or the tool so the failure cannot happen.
- Error proof it. Add something physical that stops the mistake or flags it, so nobody has to remember.
- Detect it. Add a check that reads the characteristic where the failure shows up.
- Train or remind. Useful as support. Never enough alone, and never a root cause fix.
Match an action to each cause
The worn pilot is the occurrence cause. Removing the possibility is not on the table, because the die works. Error proofing is. The team hangs a go/no-go pin at 3.970 mm on the die. The pin goes in the pilot hole at every setup, and the die is not released to the press until the setup sheet carries a signed result. The limit comes from the test. The 3.970 mm pilot finished the 2,400 piece run at 38.11, 0.09 mm inside the upper limit. The worn pilot finished over.
The escape needs detection. A fixture gage that reads hole spacing replaces the plug gage on this characteristic. It is used on the first piece, every 600 pieces and on the last piece, which is 5 readings in a 2,400 piece run. The worn pilot read 38.19 at piece 1,800, only 0.01 mm inside the limit, and 38.24 at piece 2,400. The last reading catches it, and the reaction plan sorts back to the 1,800 reading.
The system gap needs a system change. The pilot goes on the preventive maintenance list with a named owner. The 8D form gets a required field, how was the cause proven, and a report with it empty does not close.
Put an owner and a date on each
- Pilot pin check on the die setup sheet, go/no-go pin at the limit. Owner: tooling lead. Due: week 17.
- Fixture gage spacing check, first piece, every 600 and the last piece. Owner: quality technician. Due: week 17.
- Add the die pilot to the preventive maintenance list. Owner: maintenance lead. Due: week 18.
Retraining stays off the list, because as an action it would repeat the first report.
Read more: corrective vs preventive action and the free 8D report checker.
The mistake to avoid
Picking the action because it is easy to close. Ask of each action: if someone forgets, does the defect still get stopped? If not, find a stronger one.
- Read the actions on your last corrective action.
- Mark each: remove, error proof, detect or train.
- Replace any that is only training.
Open the printable Monday Board
Related on ShopFloorOps
The part, the die, the lots and every number in this book (sensor bracket BK-6139) are a made-up example. The tool sidebars show ShopFloorOps tools, which I make and sell. Every chapter teaches the step itself, so you can use your own forms. New to a term? See the quality glossary.