A Comparison Between Tandem Queues with Dependent and Independent Service Times

This paper considers tandem queues in which a given customer has equal service times at each station. The case M/M/1 → M/1 is considered in detail and the expected waiting time in the case where any given customer has independent service times at the two stations is compared with the expected waiting time in the case where any given customer has equal service times at the two stations. This comparison is based on theoretical results as well as on simulation. Tandem queues with blocking (zero queue capacity between the stations) are also considered and the waiting time and system capacity in the case where any given customer has independent service times are compared with the waiting time and system capacity in the case where any given customer has equal service times.