FPY only works if the counts are captured where the failure happens. The simplest system is a rework tag: whenever an operator or inspector finds something that must be corrected, they fill in a tag with the station, the reason from a fixed short list, and the time. The tag travels with the unit to the repair bench and is dropped in a box there. Entering count comes from the production schedule or a counter at the station.
At the end of each shift someone counts the tags per station, subtracts from the entering count and posts the FPY on a board by the line. A one-week trend chart beside it shows whether things are getting better or worse. A sudden drop of a few points in one day is a signal, not noise, when the volume is in the thousands.
Sorting the tag reasons from most to least frequent for the weakest station gives the improvement team its first target. Error-proofing the top reason, such as a tape-width check at the dispenser, usually recovers more yield than any amount of retraining.
Standard Procedure
- 1Issue a rework tag for every unit that needs correction, with station and reason code.
- 2Count tags per station at shift end and subtract from units entering to get first-time-good.
- 3Post FPY per station on a board with a one-week trend.
- 4Rank the tag reasons for the lowest station and assign the top reason to the improvement team.
- 5Recheck the FPY one week after the fix to confirm the gain held.
Lesson Summary
- ✓Capture rework at the point of failure, not from memory at the end of the shift.
- ✓The reason ranking on the tags is the action list for the improvement team.