The main purpose of control charts is to:

Control charts are statistical tools used to monitor and analyze process variations over time. The primary purpose of control charts is to determine if a manufacturing or business process is operating consistently within predefined limits. By plotting data points over time and including control limits, these charts help identify trends, shifts, or any anomalies that might indicate a deviation from standard operating procedures.

When a control chart shows that a process is stable and under control, it indicates that variations are due to common causes, which are inherent to the process. Conversely, if the chart displays points outside of control limits or patterns suggesting a trend, this signals that the process may be influenced by special causes, requiring further investigation and action to maintain process stability.

Using control charts effectively can lead to improved quality control, reduction in defects, and enhanced operational efficiency by ensuring that processes remain within the desired specifications over time.