  Tandem queues with finite buffer capacity commonly exist in practical
applications. By viewing a tandem queue as an integrated system, an innovative
approach has been developed to analyze its performance through the insight from
reduction method. In our approach, the starvation at the bottleneck caused by
service time randomness is modeled and captured by interruptions. Fundamental
properties of tandem queues with finite buffer capacity are examined. We show
that in general system service rate of a dual tandem queue with finite buffer
capacity is equal or smaller than its bottleneck service rate, and virtual
interruptions, which are the extra idle period at the bottleneck caused by the
non-bottlenecks, depend on arrival rates. Hence, system service rate is a
function of arrival rate when the buffer capacity of a tandem queue is finite.
Approximation for the mean queue time of a dual tandem queue has been developed
through the concept of virtual interruptions.
