University of Debrecen Performance Analysis of Finite-source Retrial Queueing Systems with Heterogeneous Non-reliable Servers and Different Service Policies

This paper deals with the performance analysis of multiple server retrial queueing systems with a finite number of homogeneous sources of calls, where the heterogeneous servers are subject to random breakdowns and repairs. The requests are serviced according to random and fastest free server disciplines. The novelty of this investigation is the different service rates and different service policies with the non-reliability of the servers, which has essential influence on the performance of the system, thus it plays an important role in practical modeling of computer and communication systems. All random variables involved in the model construction are assumed to be exponentially distributed and independent of each other. The main steady-state performability measures are derived, and several numerical calculations are carried out by the help of the MOSEL tool under different service disciplines. The numerical results are graphically displayed to illustrate the effect of arrival, retrial, and failure rates on the mean response time and on the overall system’s utilization.