Abstract

We see that the control chart has many uses beyond assessing process variation behavior and providing a process control methodology. The key to the control chart’s success
is the plotting of the process behavior over time. This helps identify cause-and-effect relationships, assess test method reproducibility and repeatability, and provide early warning devices to identify process shifts that may be over the horizon. We are indeed fortunate that Shewhart chose quality as his life’s work. His ideas have stood the test of time and found utility in a wide variety of situations.