Validation of Taguchi design using a quality parameter of cosmetic soap manufactured in a local industry

C. P. S. Pathirana, R. A. Dayananda, P. Dias, S. B. Nawarathne


The objective of this study is to investigate the applicability of Taguchi method to the production process of a local industry. Harishchandra Mills (Pvt.) Ltd, Matara, which is engaged in soap manufacturing process has been selected as the local industry. This process is entangled with different kinds of variables. Four critical variables - two types of oil, coconut oil (a1) and palm oil (a0), on the basis of high and low saponification values, two levels of caustic soda (b0, b1), and two different saponification temperatures, 70(c0) and 80(c1), with and without stirring process for saponification (d1, d0) were adopted. The results obtained for Total Fatty Matter (TFM) was used to calculate optimum value (Yopt) for each treatment with and without replicates. The results for Yopt for TFM with and without replicates were 75.98%, and 76.66%, respectively. The best treatment combination under this method was a1b1c1d1 for the same sequence of quality parameters given above. The same best treatment combinations were also obtained for the validation test, four-factor experiment design and block design with and without replicates.

Full Text:



Box G, Bisgard S, Fung C 1987 : An Explanation and Critique of Taguchi’s Contributions to Quality Engineering, Supplements to the Journal of the University of Wisconsion, U.S.A, 126-128.

Dayananda R.A 1992 :Fifty Year of Quality Technology, University of Sri Jayewar-denepura.

Douglas C.M 2000. Design and Analysis of Experiment, fifth edition, Arizona.

George E.P.Box, William G.Hunter, Hunter J.S 1978 : Statistics for Experiments, John Wiley & Sons.,

03.2004. Methods of Analysis of Soap, Ceylon - Standard 27:1968, Bureau of Ceylon Standards.

Nawarathne SB 2003. M.Phil thesis. Extraction of adible grade sesame oil by Controlling acid value and free fatty acid level in seeds and oil.

Pathirana C.P.S 2005. M.Sc thesis Validation of Taguchi Design Using Quality Parameters of Toilet Soap Manufactured in a Local Industry, University of Sri Jayewardenepura.

Richard R. Johnson 1996:Miller & Freund’s Probability and Statistics for Engineers. Fifth edition, Prentice Hall of India private limited, New Delhi.

Ronald E.W, and Raymond H.M.: Probability and Statistics for Engineers and Scientists, Collier Macmillan Publisher, London.

Thomas P.R 1998: Statistical Methods for quality Improvement. Wiley Series


  • There are currently no refbacks.

Creative Commons Licence
Ruhuna Journal of Science by University of Ruhuna is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

eISSN: 2536-8400

Print ISSN: 1800-279X (Before 2014)