Admission control policies for two-stage tandem queues with no waiting spaces

This study considers a two-stage no-wait tandem queueing system, in which any customer who finds all servers busy at his destination stage will be lost. If customers arrive randomly, in order to prevent the loss of customers from the second stage, an admission control is applied to determine whether a new customer shall be accepted such that all accepted customers will go through the second stage successfully. We propose an admission control policy and show that the admission conditions of this policy are the sufficient and necessary admission conditions. The rejection or loss rate of customers in such a controlled system is compared with the loss rate of a system without any admission control. It is shown that both loss rates are equal when there is only one server at the first stage.