In the problem of inventory with backorder, the total cost is F(q,s) (in Section 2, (2.1)), 0<q<s, where q is the order quantity, s is the shortage quantity. For each fixed q>0, let Kq(s)=F(q,s), 0<s<q and G(q)=min0<s<qKq(s). Also that the minimum of F(q,s) with respect to q,s is the same as the minimum of G(q) with respect to q and s=(a/(a+b))q. Fuzzify both q and s, we will have the result of the fuzzy cost G(&qtilde;). &stilde; = (a/(a+b))&qtilde;, where &qtilde; = (q1·q0·q2) is a triangular fuzzy number. Also we will have the membership function &qtilde; = (q1·q0·q2) of the fuzzy cost &qtilde; = (q1·q0·q2) and its centroid.
