Certified Production & Operations Manager (POM) Practice Exam

What does an x-bar chart help determine regarding a process?

1. Cost efficiency

2. Change in the process output's central tendency

3. Quality defects

4. Employee productivity

The correct answer is: Change in the process output's central tendency

An x-bar chart is a quality control tool specifically designed to monitor the central tendency of a process over time. It tracks the average of a sample of measurements from the process, allowing users to detect trends or shifts in that average. By plotting these averages, the x-bar chart helps identify any changes in the central tendency, which can signal whether a process is stable or if there are variations that need to be addressed. This focus on the average output means that it is particularly useful for understanding how the process is performing in terms of its typical output, and enables proactive management to maintain or improve quality. The other options do not directly relate to the primary function of an x-bar chart. For instance, while cost efficiency, quality defects, and employee productivity are important aspects of process management, they are not the primary focus of what an x-bar chart measures. The chart does not provide direct insights into cost or employee performance, nor does it specifically quantify quality defects; rather, it indicates whether the average output of the process is consistent or varying.