Fuzzy economic production for production inventory

A production cycle is defined using both production and sale, for which to a certain point the production stops until all inventories are sold out. For the planning period of T days, the function of total cost is F(q) where q represents the production quantity of each cycle. The best production quantity in the Crisp sense is qi. Fuzzification of q changes to fuzzy number (Q) over tilde; then, how to determine the best production quantity in the light of (Q) over tilde is the subject of this paper. Suppose the membership function of (Q) over tilde is a trapezoidal fuzzy number set (q(1),q(2),q(3),q(4)) satisfying the condition of 0