Mahdi Bashiri - Faculty of Engineeing, Industrial Engineering Department. Shahed University
taha H.Hejazi - Department of Industrial Engineering, Shahed University, Tehran, Iran
Hossein Badri - Department of Industrial Engineering, Shahed University, Tehran, Iran

Computer simulation is a powerfil tool in evaluating complex systems. These evaluations are usually in the from of responses to "what if" questions. Simulation optimization provides a structured approach to system design and configurations. Simulation optimization provides a structured approach to system design and configuration when analytical expression for input/output relationships are unavailable. Nondeterministic inputs and their relation will results evaluation. in this paper we propose a robust optimization method based on multiple response Surfaces (MRS) to optimiza probabilistic inventory models with multiple performance objectives. MRS optimization as a branch of experimental design is useful procedure to find a series of regression models to the responses of the simulation ,odel evaluated at several points and trying to optimize the resulting regression functions. Then a numerical example on an inventory system has been developed and its results have been compared with evolutionary algorithms to show the accuracy of the proposed method.

Experimental Design. Robust Optimization, simulation, Inventory Modeling, Multiobjective Optimization