JSE_V6_N3_RP3 Mamatha E. C.S. Reddy Ramakrishna Prasad Journal on Software Engineering 2230–7168 6 3 21 27 QBD, Markov Modulated Poisson Process, Breakdowns and Repairs, Open Queuing Networks, Batch Markov Arrival Process, Mean Queue Length Present days, various practical queuing systems extensively used in computing and communication have finite capacities and in such systems, servers are prone to failures. Queuing networks are widely used in the modeling of transaction processing systems, and their interactions among nodes in communication networks. The performance modeling of a multi-node system, with heterogeneous nodes, each node serving external as well as routed internal arrivals of jobs is considered in this paper. Results obtained using the analytical model are analyzed. January - March 2012 Copyright © 2012 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1788