Prediction and pragmatism in Shewhart’s theory of statistical control

Dr W.A. Shewhart, “founder” of the modern quality movement and inventor of the control chart, was greatly influenced by the pragmatist philosopher, C.I. Lewis. However, Lewis's influence is less clear. Shewhart did not refer to Lewis in his 1931 book and it was not until the 1939 publication of his lectures that we find references to Lewis. While Shewhart's work has been read and understood by statisticians, this paper argues that to fully understand his work, one needs a background in philosophy of science. To make the point, this paper uncovers similarities between Lewis's pragmatism and Shewhart's invention of the control chart. Not least is a theory of prediction. The paper concludes that Shewhart had formed the core of his theory before reading Lewis, and that Mind and the World Order (Lewis, C.I., Mind and the World Order: Outline of a Theory of Knowledge, Dover Publications, New York, NY, 1929) provided a convenient post hoc rationalisation. The basis for a theory of management by prediction is a significant outcome of this paper.