Kamran Rezaei - Dept. of Industrial Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran
Hamed Nematian - Dept. of Industrial Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran

Six sigma has been considered as a business strategy that employs a well-structured continuous improvement methodology to tackle process variability and drive out waste from the business processes with the application of statistical tools and techniques in a rigorous manner. Nowadays there is a wider acceptance, growth and investment of six sigma and design for six sigma (DFSS) in both manufacturing and service industries. Although initially employed to improve existing processes, six sigma principles are also applied to design and redesign processes to ensure achievement of high levels of quality. This effort is known as design for six sigma (DFSS). This paper first examines the differences and similarities of six-sigma improvement methodology (DMAIC) compared with the DFSS approach. This work illustrates the use of analytical hierarchy process (AHP), a multiple criteria decision-making technique, for the evaluation of six-sigma projects in order to determine when the six-sigma approach becomes a priority over DFSS.

Six Sigma, Analytical hierarchy Process, DMAIC, Design For Six Sigma, Process Management