ASQ Exam CQE Topic 3 Question 113 Discussion

The chart provided is a control chart used to monitor process variation over time.

Control charts have upper control limits (UCL) and lower control limits (LCL) that represent the threshold of acceptable variation.

Points X and Y, which lie outside the control limits, indicate special causes of variation. These are deviations caused by specific, identifiable factors rather than inherent process noise.

Region Z, where data points are consistently below the mean and approaching the LCL, suggests a trend indicating a shift due to special causes.

Reference: According to ISO 9001 and the ASQ, control charts are utilized to detect special causes of variation, which signal that a process is out of control and requires investigation.