Abstract
We consider an FMC system having a single numerical controlled machine with a finite buffer storage and an automatic tool changer. The automatic tool changer has a finite capacity of tool magazine. So far, tool switching times at numerical controlled machines have been assumed to be very small and neglected. However, it is found that the tool switching time in FMC systems significantly affects the system performance at high level of machine utilization. This paper considers the FMC model with an automatic device which can change tools between the tool magazine and the tool storage so that two types of materials are processed. We apply the queueing theory to analyze the performance of the FMC model. The moment generating function of waiting time is derived and numerical results for the average performance measures are presented.
