Optimization of fuzzy production inventory models

In this paper, we introduce two fuzzy production inventory models with fuzzy parameters for crisp production quantity, or for fuzzy production quantity. The fuzzy total production inventory costs of these models under the fuzzy arithmetical operations of Function Principle are proposed. The final purpose is to find optimal solutions of these models by using Graded Mean Integration Representation method for defuzzifing fuzzy total production inventory cost, and by using Extension of the Lagrangean method for solving inequality constrain problem. Furthermore, we find that the optimal solutions are all crisp real numbers. In addition, when the fuzzy parameters (fuzzy inventory cost, fuzzy demand, fuzzy setup cost, fuzzy demand rate, and fuzzy production rate) are all crisp real numbers, the optimal solutions of our proposed models can be specified to meet classical production inventory models. (C) 2002 Elsevier Science Inc. All rights reserved.