Which of the following statements is NOT true about process control charts?
A) Process control charts are an important part of statistical process control.
B) Process control charts are used to monitor processes to enable conclusions to be drawn about whether . or not the process is in control.
C) Process control charts can tell you that the process has changed, even though it has yet to produce a defect.
D) In order for a process control chart to be used to prevent defects from occurring, the capability index must be greater than 1.

Question

Quizplus · Accepted Answer

Process control charts are tools used to determine the stability of a process and to monitor its performance over time. They can indeed indicate changes in a process before defects occur (C), and they are a fundamental part of statistical process control (A). They are designed to help draw conclusions about the state of control of a process (B). However, the statement about the capability index (D) is misleading. The capability index (such as Cp, Cpk) is a separate measure from what is directly monitored by process control charts. While a higher capability index indicates a more capable process, it is not a prerequisite for using process control charts to prevent defects. Process control charts are used to monitor the process variability and stability, not directly its capability index.

Which of the Following Statements Is NOT True About Process