Analysis of departure process on the population constrained tandem queueing network with 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 arriving at the queueing network when there are more than k customers are forced to wait in an external queue. The arrival process to the queueing network is assumed to be arbitrary. It is known that the queueing network with population constraint and constant service times can be transformed into a simple network involving only two nodes. In this paper, the departure process from the queueing network is examined using this simple network. An approximation can be calculated with accuracy. Finally, validations against simulation data establish the tightness of these.