THROUGHPUT ESTIMATION IN CYCLIC QUEUING-NETWORKS WITH BLOCKING

The paper presents a new approach for estimating the throughput of a c losed queueing network with exponential servers, finite buffer capacit y and a blocking after service discipline. The problem is tackled by d ecomposing the network. The population constraint is enforced by requi ring that the sum of the expected number of customers in the various s ubsystems is equal to the population size. Each subsystem is analyzed as an M/M/1/C-i + 1 queue with state-dependent arrival and service rat es. The rationale behind this last assumption is that the behavior of the system at a given time is affected by the history of blockings and starvations. The results obtained by applying the proposed algorithm to a set of test problems show a good agreement with those obtained wi th simulation, the difference on the maximum throughput of the network being of the order of 3%. The obtained results also compare favorably with those described in the literature.