ANALYSIS OF AN OPEN TANDEM QUEUING NETWORK WITH POPULATION CONSTRAINTAND CONSTANT SERVICE TIMES

We consider an open tandem queueing network with population constraint and constant service times. The total number of customers that may be present in the network can not exceed a given value K. Customers arri ving at the queueing network when there are more than K customers are forced to wait in an external queue. The arrival process to the queuei ng network is assumed to be arbitrary. We show that this queueing netw ork can be transformed into a simple network involving only two nodes. Using this simple network, we obtain an upper and lower bound on the mean waiting time. These bounds can be easily calculated. Validations against simulation data establish the tightness of these bounds.