What is the aim of control limits in a control chart?

In the context of control charts, the aim of control limits is to establish an acceptable range of variation in a process. Control charts are statistical tools used in quality control to monitor process behavior over time. They consist of a central line representing the average of the process, along with upper and lower control limits that indicate the boundaries of acceptable variation.

The purpose of these control limits is to identify when a process is operating within a state of control or when it shows signs of variability that may indicate a potential problem. When data points fall within these limits, it suggests that the process is stable and consistent; conversely, points outside the limits signal that corrective action may be necessary as they indicate unusual variations that could lead to defects or quality issues.

While assessing employee productivity, managing customer expectations, and determining the severity of defects can all be relevant in a broader context of operational performance and quality management, they do not specifically pertain to the primary function of control limits in a control chart. Control limits are fundamentally about understanding and managing the inherent variability in processes, which is crucial for maintaining quality standards in production and service delivery.