When using a control chart, the observations outside the upper and lower product specification limits are ordinarily regarded as non random and worth investigating.

Question

Quizplus · Accepted Answer

Observations outside the upper and lower product specification limits are actually beyond the control limits, not the specification limits. These observations are considered non-random and worthy of investigation because they indicate a potential problem in the process. Knowing which observations are beyond the specification limits and why is important for evaluating the process's capability to produce quality products.

When Using a Control Chart, the Observations Outside the Upper