Which is a tool of statistical quality control?

Answer 1

Perhaps the most characteristic tool of statistical quality control is the control chart. In its simplest form the control chart is a continuous record of some feature of a process that is deemed to indicate whether that process is 'in control' or not. As long as the control chart shows that the process is within, say, three standard deviations of its mean behaviour it will be considered 'in control'; otherwise not, and steps to correct it taken.

Before this system can be put into operation experimentation will be necessary, which implies the need for experimental design. One the system is in place, attempts are often made to find ways of improving the process under control to reduce the number of departures outside the control limits, or to narrow the limits.

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