Bounds for the Expected Delays in Some Tandem Queues

Tandem queues are analyzed. An upper bound for the stationary expected delay in front of the second server is found for a sequence of two queues in tandem where the first server has deterministic service times, the second server has general service distribution, and the arrival process is an arbitray renewal process. The result is extended to the case of n queues in tandem where all the servers except the last one have constant service times.