Chapter 20. Six Sigma
A. van der Wiele, J. D. van Iwaarden, B. G. Dale and A. R. T. Williams
Motorola created the concept of six sigma in the mid-1980s to improve the performance of key processes, productivity and quality and at the same time reduce costs (Bhote and Bhote 1991). The main factor behind its development was continuous improvement in the manufacture of complex devices involving a large number of parts with a high probability of defects in the end product. At the same time, customers were demanding that Motorola improve quality in their final product offerings. This external driver supported the need for continuous improvement.
The goal of six sigma is value creation through quality improvement. The process by which this is attained would involve training of employees in tools and techniques as well as a problem-solving protocol. Six sigma makes use of quality engineering methods within a defined problem-solving structure to identify and eliminate process defects and solve problems and in this improve yield, productivity, operating effectiveness, customer satisfaction, etc. (Bhote and Bhote 1991; Harry and Schroeder 1999; McFadden 1993; Pande et al. 2000; Pyzdek 2003). It is based on the well-established quality management ideas of understanding and eliminating the causes of variation and robust designing for manufacture and assembly. Therefore, its roots are in Statistical Process Control (SPD), back in the 1920s (Bisgaard and de Mast 2006) – but it has been ...