An explanation and critique of taguchi's contributions to quality engineering

TLDR

Interest and controversy surround Professor Genichi Taguchi’s statistical methods for quality improvement, which include fractional factorial designs, orthogonal arrays, parameter design, signal‑to‑noise ratios, loss functions, accumulation analysis, minute analysis, and life‑test data analysis. This paper explains Taguchi’s contributions to quality engineering and critically evaluates his statistical methods. The authors conclude that while Taguchi’s ideas are valuable for engineers, his statistical techniques are often inefficient, unnecessarily complex, and should be replaced or suitably modified. References are appended for further detail.

Abstract

Abstract Recently there has been much interest and some controversy concerning the statistical methods employed by Professor Genichi Taguchi of Japan for improving the quality of products and processes. These methods include the use of fractional factorial designs and other orthogonal arrays, parameter design to minimize sensitivity to environmental factors, parameter design for minimizing transmitted variation, signal‐to‐noise ratios, loss functions, accumulation analysis, minute analysis and the analysis of life test data. This paper explains some of Taguchi's contributions to quality engineering and also provides a critical evaluation of his statistical methods. Our conclusion is that although on the one hand, Professor Taguchi's quality engineering ideas are of great importance and should become part of the working knowledge of every engineer, on the other hand, many of the techniques of statistical design and analysis he employs to put these ideas into practice are often inefficient and unnecessarily complicated and should be replaced or appropriately modified. In this short article only an overview is attempted, but references are appended where these matters are discussed in greater detail.