What does a control chart monitor?

A control chart serves as a tool for monitoring the variability of a process over time. It visually displays data points plotted in time order, allowing users to identify trends, shifts, or any unusual variations in the process. By analyzing the patterns in the control chart, organizations can determine if a process is operating within its predetermined limits or if it requires adjustments to achieve consistent quality.

This monitoring capability is essential in quality control, as it helps to distinguish between common causes of variation, which are inherent to the process, and special causes that may indicate a need for investigation and corrective action. In this way, control charts support the continuous improvement of processes, ensuring that products meet quality standards consistently over time.