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Six Sigma Solutions and its Benefit-Cost Ratio for Quality Improvement

Authors: S. Homrossukon, A. Anurathapunt


This is an application research presenting the improvement of production quality using the six sigma solutions and the analyses of benefit-cost ratio. The case of interest is the production of tile-concrete. Such production has faced with the problem of high nonconforming products from an inappropriate surface coating and had low process capability based on the strength property of tile. Surface coating and tile strength are the most critical to quality of this product. The improvements followed five stages of six sigma solutions. After the improvement, the production yield was improved to 80% as target required and the defective products from coating process was remarkably reduced from 29.40% to 4.09%. The process capability based on the strength quality was increased from 0.87 to 1.08 as customer oriented. The improvement was able to save the materials loss for 3.24 millions baht or 0.11 million dollars. The benefits from the improvement were analyzed from (1) the reduction of the numbers of non conforming tile using its factory price for surface coating improvement and (2) the materials saved from the increment of process capability. The benefit-cost ratio of overall improvement was high as 7.03. It was non valuable investment in define, measure, analyses and the initial of improve stages after that it kept increasing. This was due to there were no benefits in define, measure, and analyze stages of six sigma since these three stages mainly determine the cause of problem and its effects rather than improve the process. The benefit-cost ratio starts existing in the improve stage and go on. Within each stage, the individual benefitcost ratio was much higher than the accumulative one as there was an accumulation of cost since the first stage of six sigma. The consideration of the benefit-cost ratio during the improvement project helps make decisions for cost saving of similar activities during the improvement and for new project. In conclusion, the determination of benefit-cost ratio behavior through out six sigma implementation period provides the useful data for managing quality improvement for the optimal effectiveness. This is the additional outcome from the regular proceeding of six sigma.

Keywords: Process Improvement, benefit cost ratio, Six Sigma Solutions, QualityManagement

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[1] Hahn, G.J., Doganaksoy, N., Hoerl, R., W., "The Evolution of Six Sigma," Quality Engineering, vol. 12, Issue 3, 2000, pp. 317-326.
[2] Xingxing Zu, Lawrence D. Fredendall, Thomas J. Douglas, "The evolving theory of quality management : The role of Six Sigma," Journal of Operation Management, vol.26, 2008, pp. 630 - 650
[3] U. Dinesh Kumar, David Nowicki, "On the optimal selection of process alternatives in Six Sigma implementation," Journal of Production Economics, Vol.111, 2008, pp.456 - 467
[4] Chung-Ho Wang, Yi Hsu, "Enhancing rubber component reliability by response model," Journal of Computer & Industrial Engineering, vol.57, 2009, pp. 806 - 812
[5] Choa-Ton Su, Chia-Jen Chou, "A systematic methodology for the creation of six sigma project : a case study of semiconductor foundry," Expert System with Applications, vol. 34, 2008, pp. 2693-2703.
[6] Satya S. Chakravorty, "Six Sigma programs : An implementation model," International Journal Production Economics, vol. 119, 2009, pp.1-16.
[7] Young Hoon Kwak and Frank T. Anbari, "Benefits, obstacles, and future of sic sigma approach," Technovation, vol. 26, 2006, pp. 708-715.
[8] C. Belfield, H.M. Levin, "Cost-Benefit Analysis and Cost-Effectiveness Analysis," International Encyclopedia of Education, 2010, pp. 199-203.
[9] Brian, T. Yates, "Cost-inclusive Evaluation : A Banquet Approaches for Including Costs, Benefits, Cost-Effectiveness and Cost-Benefit Analyses in your Next evaluation," Evaluation and Program Planning, vol. 32, 2009, pp 52-54.
[10] David Beevis, "Ergonomics-Costs and Benefits Revisited," Applied Ergonomics, vol. 34, 2003, pp.491-496.
[11] Smith, D., Blakeslee, J.,Knooce., Strategic Six Sigma, Plentice-Hall, Upper Saddle River, NJ, 2002.
[12] Banuelas, R., Tennant, C., Tuersley, I., Tang, S., "Selection of Six Sigma projects in the UK," The TQM Magazine, vol. 18, issue 5, 2006, pp.255-262.
[13] Roger. Shoeder, "Six Sigma : Definition and Underlying Theory," Journal of Operations Management, vol.26, 2008, pp 536-554.
[14] Mast, J.D., Bisgaard, S., "The science in Six Sigma," Quality Progress, vol. 40, issue 1, 2007, pp. 25-29.
[15] A.K. Sahoo, M.K. Tiwarib, A.R. Mileham, "Six Sigma based approach to optimize radial forging operation variables", Journal of Materials Processign Technology, vol. 202, 2008, pp. 125 - 136.
[16] Forrest W. Breyfogle III, Implementing Six Sigma Smarter Solutions Using Statistical Methods, John Willey, 1999, ISBN 0-471-29659-7.
[17] Henry Malcom Steiner, Engineering Economics Principles, 1992, Mc graw-Hill pp. 125-126.
[18] Evans, J.P./ Lindsay, W.M., Managing for Quality and Performance Excellence, seventh ed., South-Western, Mason, OH, 2008.
[19] Bendell, T., "A review and comparison of Six Sigma and the lean organizations," The TQM Magazine, vol.18, issue 5, 2006, pp.255-262.
[20] Mader, D.P., "Lean Six Sigma-s evaluation," Quality Progress, vol.41, issue1, pp.40-48.
[21] Johnson, A.,Swisher, B., " How six sigma improves R&D," Research Technology Management, vol. 46 issue 2, 2003, pp. 12-15.
[22] Gitlow, H.S., Levine, D.M., Six Sigma for Gressn Belts and Champions: Foundation, DMAIC, Tools, Cases, and Certification, Prentice Hall N.J., 2005.
[23] J. Banks, The Essence of Total Quality Management, Prentice Hall, Eagle wood Cliff, N.J., 1992.
[24] Peter E.D. Love, Zahir Irani, "A project management quality cost information system for construction industry," Information & Management, vol.40, 2003, pp.649-661.