An EPQ model with two levels of trade credit policy under supplier credits linked to ordering quantity based on the triangular fuzzy numbers

In real world, there are many uncertain conditions which cannot be absolutely pre-determined or controlled by the decision maker. Then, by the empirical experience in the market behavior, there are no fixed carrying cost rate, interest paid rate and interest earned rate. In this paper, we will extend Chen et al. [1] model with fuzzification in the carrying cost rate, interest paid rate and interest earned rate, simultaneously, based on the triangular fuzzy numbers to fit the real world. Then, in our new fuzzy model, we will discuss some conditions or theorems to find the optimal solution for the total variable cost per unit time in fuzzy sense. Moreover, we will take some examples to illustrate our proposed model.