Discovering that a process is out of control is not a terrible event. It should not be hidden from supervisors, managers, auditors, quality control experts, or, most important, customers. In a sense, it is an event that should be celebrated because it gives the process owner an opportunity to improve the process.
Robert Hoyer & Wayne Ellis 1996
In Chapter 5, we discussed how to calculate control limits for several different types of control charts. In this chapter, we discuss the sufficiency, organization, and arrangement of process performance measures required for effective use of control charts.
We have seen that, among the factors used to calculate control limits, the number ...