A queueing network model for flexible manufacturing systems with tool management

Abstract

The analytical model in this paper allows the evaluation of the performance of a flexible manufacturing system (FMS) with a tool management system. Design parameters such as the transportation time for tools to machines, as well as the number of transportation vehicles for tools, are explicitly considered. The part and the tool transportation system are modeled as two interacting closed queueing networks. The classical convolution algorithm is used to evaluate the part transportation system and mean value analysis approximation is applied to evaluate the tool transportation system. The resulting set of nonlinear equations allows then to estimate important system parameters such as the throughput of parts, the utilization of the tool transportation vehicles and the service interruptions caused by a tool supply order.