Design of a variable path tandem layout for automated guided vehicle systems

The partitioning of a tandem layout for an automated guided vehicle (AGV) system directly affects the system performance. Determining the location of the transfer points between zones is another important issue in the design of a tandem layout. In this paper, a heuristic partitioning algorithm for a tandem AGV system based on the concept of variable path routing within a zone is developed. Transfer points are simultaneously determined during the network partitioning process. The algorithm assumes the prior existence of a conventional and unidirectional layout. The problem of interest is one of converting the existing, conventional layout to a variable path based tandem AGV system layout. A comparison between the conventional and the tandem AGV system with respect to system performance under the same operating conditions is presented. The results show that the variable path based tandem layout requires a smaller number of vehicles in most situations than the equivalent conventional layout. In addition, the total vehicle use time of a tandem layout is smaller than that of the conventional layout.