Certified Production & Operations Manager (POM) Practice Exam

What can be concluded about the process capability index Cpk?

1. It is always equal to 1.

2. The larger the Cpk, the more units meet specifications.

3. It indicates a process that is always in control.

4. Smaller values are always preferable.

The correct answer is: The larger the Cpk, the more units meet specifications.

The process capability index Cpk is a crucial measure in quality management that assesses how well a specific process can produce output within specified limits. When Cpk is larger, it indicates that the process is centered within the specification limits and that there is a greater probability that the produced units will meet those specifications. A higher Cpk value signifies that there is less variation in the process and that the process output is more consistently within acceptable range, thus increasing the likelihood of producing units that conform to the desired specifications. This relationship directly leads to improved quality and customer satisfaction, as fewer defects arise from the production process when Cpk is higher. The other options do not accurately represent the implications of the Cpk measure. For instance, it is not true that Cpk is always equal to 1, as this value can vary based on process performance. Additionally, while a higher Cpk typically suggests a more capable process, it doesn't mean the process is always in control, which is a separate consideration related to process consistency over time. Lastly, smaller Cpk values are not preferable as they typically indicate more output falling outside of the specified limits, which translates to lower quality output.