We are currently using 3 tests to determine control. They are any point outside of the control limits, 7 points ascending or descending, and 7 points above or below the centerline. Our question is if we have a point (subgroup #3) above the upper control limit and we correct our process, do the "counters" for the 7 point tests reset? Our software package will show that subgroup #3 is out-of-control and subgroup #7 is also out-of-control if it is the 7th above the centerline. I would think a second adjustment would be premature until we have had 7 subgroups AFTER the corrective action was taken.
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