%L scholars13 %J IFAC Proceedings Volumes (IFAC-PapersOnline) %O cited By 0 %R 10.3182/20050703-6-cz-1902.02272 %D 2005 %K Cost functions; Decision making; Fuzzy set theory; Fuzzy systems; Linear programming; Manufacture; Optimization; Planning; Production control, Decision-making problem; Degree of satisfaction; Fuzzy linear programming; Fuzzy optimization; Industrial production; Manufacturing units; Optimal cost function; Product mix, Membership functions %X The modern trend in industrial application problem deserves modeling of all relevant vague or fuzzy information involved in a real decision making problem. in this paper the usefulness of the proposed S-curve membership function is established using a real life industrial production planning of a chocolate manufacturing unit. The unit produces 8 products using 8 raw materials; mixed in various proportions by 9 different processes under 29 constraints. A solution to this problem establishes the usefulness of the suggested membership function for decision making in industrial production planning. The objective of this paper is to find the optimal cost to produce 8 products using modified Scurve membership function as a methodology. The fuzzy linear programming approach is used to solved this problem. The optimal cost function is obtained respect to two major factors of degree of satisfaction and vagueness. Copyright © 2005 IFAC. %P 52-56 %I IFAC Secretariat %V 16 %A P.M. Vasant %A N.N. Barsoum %T Fuzzy optimization of cost function in product mix selection problem