1) an X hi/lo-R control chart for every finish tool with control limits of approx. 75% of the tolerance (to start)
2) a sampling frequency of the number of parts it takes for the tool wear from the lower control limit to the upper control limit for an OD or outer length (opposite for ID or inner length) - tool wear rate - divided by 7
3) operators trained NOT to "run to the mean," but to set to control limits and ONLY adjust when the process hits a control limit.
4) make sure the gages have adequate gage R&R (ndc>=10) for charted features.
If you follow those suggestions for precision machining, you will make good parts of high quality with the fewest operator interventions.
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