Digital Library

of the European Council for Modelling and Simulation



Performance Evaluation Of Dependent Two-Stage Services


Werner Sandmann

Published in:


ECMS 2007 Proceedings

Edited by: Ivan Zelinka, Zuzana Oplatkova, Alessandra Orsoni


ISBN: 978-0-9553018-2-7

Doi: 10.7148/2007


21st European Conference on Modelling and Simulation,

Prague, June 4-6, 2007


Citation format:

Sandmann, W. (2007). Performance Evaluation Of Dependent Two-Stage Services. ECMS 2007 Proceedings edited by: I. Zelinka, Z. Oplatkova, A. Orsoni (pp. 74-79). European Council for Modeling and Simulation. doi:10.7148/2007-0074.



In many scenarios services are provided in successive stages. While tandem queues appropriately reflect the structure of such scenarios, the typical assump- tion that service times at different stages are inde- pendent often does not fit to reality. We examine, via simulation, the impact of dependencies among service times on expected customer waiting times. The usual network simulation overhead caused by event list handling is avoided by an extension of the Lindley recursion to the two-stage case. Numerical results are presented for exponentially and uniformly distributed service times with different types of de- pendencies and varying server utilizations.

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