Certified Quality Engineer (CQE) Practice Exam 2025 - Comprehensive All-in-One Study Guide for Exam Success!

A control chart is a statistical tool that helps monitor the performance of a process over time, making it pivotal in quality control and assurance. It provides a visual representation of how a process behaves by displaying data points of a particular metric against time, along with upper and lower control limits. These limits help in identifying trends, shifts, or variations in the process that may require investigation or corrective action.

The focus of a control chart is to understand process stability and variability, thereby facilitating better decision-making based on empirical data. By tracking performance over time, it can indicate whether a process is in control (operating within expected variations) or out of control (showing unacceptable levels of variation), allowing organizations to take action to maintain or improve quality.

In contrast, the other options, such as customer satisfaction, product training costs, and employee productivity, do not directly relate to process monitoring in the same structured statistical way that control charts do. While these aspects may be influenced by process performance, they are not the primary focus or function of control charts in the realm of quality engineering.