Six-Sigma is a newer version of Total Quality Management (TQM), and its fundamental principle is to reduce defects in processes. The traditional approach to calculate the value of n for an n-sigma process can be confusing to prospective six-sigma practitioners, because the three values of interest (viz., process capability ratio, process capability index, and n) are always different. In this paper, we present a new formula that is less confusing, and yet serves the purpose of checking how good a given process is. We apply this formula for a crucial issue (selection of potential recovery facilities) identified in the literature for reverse supply chain design. The CPC chart in the literature for selection of potential suppliers uses the process capability index alone. Since the process capability ratio too is required for judging the quality of a facility, we use the new formula for building a chart for selection of potential recovery facilities.


Originally published in the Proceedings of the SPIE International Conference on Environmentally Conscious Manufacturing VI, Boston, Massachusetts, pp. 139-148, October 1-3, 2006


Six-Sigma, Total Quality Management (TQM), Reverse Supply Chain, Supply Chain Quality, Supply Chain

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Copyright 2006, Society of Photo-Optical Instrumentation Engineers


This paper was published in Proceedings of SPIE (Volume 6385) and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

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