Fuzzy inventory with backorder for fuzzy total demand based on interval-valued fuzzy set

It is difficult to determine the fixed total demand r0 in an inventory problem with backorder in a whole plan period. We will fuzzify it as R=‘near r0’. In this article, we will classify R into three kinds: (1) fuzzy total demand with triangular fuzzy number (Section 2), (2) fuzzy total demand with interval-valued fuzzy set based on two triangular fuzzy numbers (Section 3), (3) fuzzy total demand with interval-valued fuzzy set based on two trapezoidal fuzzy numbers (Section 4). We will find the corresponding order quantities and the shortage inventories, respectively.