Question

How many control charts are normally used for statistical control of variables?

(a) 1

(b) 2

(c) 3

(d) 4

The question was posed to me by my college professor while I was bunking the class.

Question is taken from Tools and Techniques of TQM topic in division Measuring Machines & Total Quality Management of Engineering Metrology

Answer 1

Right option is (c) 3

To explain I would say: Three control charts are normally used for statistical control of variables. These are i) Mean chart, ii) Range chart, and iii) standard deviation charts. Control charts help in the understanding of inherent capability of process and bring the process under control.