A hybrid approach for design of automated material handling system

With developing technology, usage of AGV systems as material handling equipment is getting very common. In spite of the advantages of this system, the initial investment costs are very high. It is a fact that the biggest portion of investments costs of AGV systems is the vehicle costs. So determining the minimum number of vehicles required is very important.All of the analytic models developed for determining the number of the vehicles in literature, uses an efficiency multiplier which can be determined only by previous experiences. The values of this multipliers which has been determined independent from the system analyzed, have a considerable effect on result. On the other hand, simulation models which don?t have such disadvantage are expensive and require more time. Furthermore, these models require too many test runs in order to reach result. In some cases, number of test runs make the problem impossible to solve.In this study, an integrated hybrid approach that uses simulation model and heuristic algorithm has been developed to determine the minimum number of required vehicles and reorder points that minimize the work in process in AGV systems. In the further stages of study, this approach has been applied on an AGV system that is designed for a real manufacturing system. The simulation model is constructed using Flexsim simulation software. Later on, same problem solved by a an analytic model which developed by Egbelu (1987). Then the results that evaluated by both methods are compared to assess the efficiency of the method developed in this study. As a result, it?s seen that it is possible to reach to the accurate result with less test runs using the hybrid approach.