Decide what proof counts before you know the result, and write it so it can fail: the measure, a window that includes the failure cycle, the pass line, one owner with a review date, and what happens on a fail. Collect proof as you go, close the action on evidence at the review, and reopen it if the pass line is missed.
Friday, week 17, before the next run starts. You are about to do the one thing the first 8D skipped: decide what proof will count, before you know the result.
The first effectiveness check said no complaints for 30 days. It could not fail. Long runs of this die happen about every 8 weeks. A 30 day window passes without a single long run in it.
Write the check first
Write it before the fix goes in, and write it so it can fail. Five parts:
- The measure. Customer returns for hole spacing, and our own spacing readings at the press.
- The window. Long enough to include the failure cycle. Here it is two long runs, 8 weeks each, plus 2 weeks for the customer to report. That is 18 weeks.
- The pass line. No returns for spacing. Every end of run reading inside 37.80 to 38.20 mm. The pin check signed on every setup.
- The owner and the review date. One person, and a date in the calendar: week 35.
- What happens on a fail. The corrective action reopens. It does not get a new number and it does not get quietly extended.
Collect proof as you go
Do not wait until week 35 to start looking. Pull the end of run readings after each long run and attach them. Count the signatures on the setup sheets. By the review, the file should hold nearly everything, and the review is a decision.
A return reported in week 34 still fails the check, even with the window nearly closed. Say that in the plan so nobody argues about it later.
Close it on evidence
At the review, read the readings, the signatures and the customer record. If all of it meets the pass line, close the action and write what you saw. If not, reopen it and name the line it missed. The old report, the new report and the check stay linked as one file.
The old report closed the day the training ended. This one stays open for 18 weeks after the fix goes in.
Read more: how to run an effectiveness check. Book 1 covers the same step in Prove It Worked.
The mistake to avoid
Setting a window shorter than the failure cycle. If the defect only shows up on a long run, a short window can pass every time. Find out how often the failure can happen and cover at least two of them.
- Open the check on your last closed action.
- Compare its window with the failure cycle.
- Lengthen the window if it is shorter.
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.