56.1 OVERVIEW

Six Sigma is a business process that allows companies to drastically improve their bottom line by designing and monitoring everyday business activities in ways that minimize waste and resources while increasing customer satisfaction. ¹ It is a strategy driven, process focused, and project enabled improvement discipline with the goal of defect-free output.

Six Sigma evolved from a quality initiative at Motorola, Inc. in the mid-1980s. Observations showed that early field failures of products could be traced to those which had been reworked while those that were produced defect free did not exhibit early failures. Based on these findings Motorola launched an effort to reduce defects by preventing them from happening in the first place. This required that they focus on the processes that produced the products as well as the design of the product itself. There were many ways for products to fail. In order to assure that products could be made defect free, the chance of each possible type of defect had to be reduced almost to zero. Defects were associated with customer critical-to-quality (CTQ) characteristics or CTQs. Motorola realized that each CTQ would need to have a frequency of defects in the range of 3.4 defects per million opportunities (DPMO) to assure that a product with multiple CTQs would work correctly and not fail in the field. Characteristics that achieved a DPMO of 3.4 were considered to be at...