ABSTRACT
We now begin the study of a most powerful and versatile set of tools for the analysis and improvement of a production process. These tools are called ‘‘control charts’’. They were first invented by Dr. Walter A. Shewhart of the Bell Telephone Laboratories in 1924, and developed by him and his associates in the 1920s. He published a complete exposition of the theory, practical application, and economics of control charts in 1931 (Shewhart, 1931). Seldom has a whole field of knowledge been so well explored and its applications so well pointed out in the first publication in a field. So basic and applicable are control charts that new uses are continually being found in all sorts of products and industries. And yet control charting methods are simple enough to be learned and applied by one with even very modest mathematical background.
