Abstract
The number of vehicles (vehicle fleet size) in automated material handling system (AMHS) significantly influences cost of equipments and efficiency of production. However, it is not an easy task to decide the number of vehicles required in the system due to the complexity and uncertainty of manufacturing system. In this research, we propose a new formulation to determine the optimal number of vehicles of the AMHS so as to achieve the minimal vehicle cost, while satisfying transportation requirement. Furthermore, we develop a simulation-based methodology, called simulation sequential metamodeling, to solve the problem. Numerical experiments show that the proposed method outperforms the traditional approaches, especially in the problems with larger number of constraints or variance level. An empirical study is conducted to verify the viability of the proposed method.