Charles L Caristan, PhD
Published By: SME
Six Sigma encompasses a quality methodology aimed at continuously improving outputs based on criteria set by customers. Outputs are generally chosen as specific key critical specifications within the five outputs listed in the fishbone diagram: environment, safety, quality, productivity, and profitability. What makes the six-sigma methodology appealing to the corporate world is that the end result translates macroscopically but directly into tangible financial savings by improving capacity and productivity while reducing the cost of poor quality. The six-sigma definition of process capability differs from Cpk in that it considers arbitrarily skewing by 1.5 sigma from a normal distribution, for which the mean value is centered between LSL and USL. The path to six-sigma capability may take several iterations of continuous improvement actions. These actions are to be decided and implemented in a five-phase process: define, measure, analyze, improve, and control (DMAIC).