In the control chart used in the statistical process control methodology, the sample values will fall within upper control limit (UCL) and the lower control limit (LCL) if the process is affected only by _____ causes of variation.
A) common
B) assignable
C) non-random
D) special

Question

Quizplus · Accepted Answer

The upper and lower control limits are based on the common causes of variation, which are inherent to the process and expected to occur. Assignable causes of variation, non-random or special causes, are outside the normal range of variation and can be identified and corrected. If only common causes of variation are present, the process is considered to be in statistical control, and the sample values will fall within the UCL and LCL.

In the Control Chart Used in the Statistical Process Control