Abstract
In this paper the author indicates the possibility of a new approach to control-chart technique in connection with manufacturing processes. The advantages of quality control of product are widely recognized, and the principles pioneered by Walter A. Shewhart in 1924 have since that time been the object of intensive investigation. Primarily, the present paper is concerned with control with respect to a given standard. By analyzing hypothetical examples, illustrated graphically, the basis of the control-chart method is clarified. However, in exemplifying the control-chart technique, the author indicates a method of reversing the usual procedure, by creating uncontrolled conditions, and then noting whether the tests made locate the “assignable causes” which have been introduced in the experiments. The investigation is carried out with the aid of H. C. Tippett’s tables of “Random Sampling Numbers.”
