Inventory without backorder with fuzzy total cost and fuzzy storing cost defuzzified by centroid and signed distance

In the total cost of inventory without backorders, we fuzzify the total demand r and the cost of storing one unit per day a to the triangular fuzzy numbers &rtilde; and ã in a plan period, respectively. For any order quantity q>0, we get the fuzzy total cost Hq(&rtilde;, ã) in terms of &rtilde; and ã. Then we defuzzify by the centroid and the signed distance methods. We can find the minimum total cost and the optimal order quantity by defuzzifying the total cost through the centroid method. We can do the same thing by the signed distance method. Then we compare the results obtained by these two methods.