For control chart,the lower and upper control limits are usually set at:
A) five standard deviations from the centerline.
B) four standard deviations from the centerline.
C) three standard deviations from the centerline.
D) two standard deviations from the centerline.
E) one standard deviation from the centerline.

Question

Quizplus · Accepted Answer

The most commonly used and recommended setting for control chart limits is to place them at three standard deviations from the centerline. This is based on statistical theory and ensures that the control chart will detect almost all shifts in the process mean or variation. It also strikes a balance between having too many false alarms and not detecting important process changes.

For Control Chart,the Lower and Upper Control Limits Are Usually