Certified Production & Operations Manager (POM) Practice Exam

If the mean of a sampled set of items is outside the control limits, what does this indicate about the process?

1. It is functioning efficiently.

2. It is likely out of control and the cause should be investigated.

3. It requires no further scrutiny.

4. It is within acceptable limits.

The correct answer is: It is likely out of control and the cause should be investigated.

The mean of a sampled set of items being outside the control limits is a critical indicator of the state of a process. Control limits are statistical boundaries that help determine the acceptable range of variation in a process. When the mean falls outside these limits, it signals that the process may not be performing as expected and is likely influenced by special causes that warrant further investigation. This situation suggests that the variations in the process may be due to factors that are not part of the normal operating conditions, implying that corrective action or a deeper analysis is necessary to understand the underlying issues affecting the process's performance. In summary, this answer emphasizes the importance of monitoring process variation and the need for corrective measures when deviations occur, making it a key aspect of quality control and process management. The other choices suggest scenarios where the process is functioning efficiently, requiring no scrutiny, or remaining within acceptable limits, all of which do not align with the implications of the mean being outside the control limits.