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Stochastic comparisons for fork-join queues with exponential processing times

Published online by Cambridge University Press:  14 July 2016

Esther Frostig*
Affiliation:
Haifa University
Tapani Lehtonen*
Affiliation:
Helsinki School of Economics
*
Postal address: Department of Statistics, Haifa University, Haifa, Israel, 31905.
∗∗Postal address: Helsinki School of Economics, Runebergink 14-16, 00100 Helsinki, Finland.

Abstract

Consider a fork-join queue, where each job upon arrival splits into k tasks and each joins a separate queue that is attended by a single server. Service times are independent, exponentially distributed random variables. Server i works at rate , where μ is constant. We prove that the departure process becomes stochastically faster as the service rates become more homogeneous in the sense of stochastic majorization. Consequently, when all k servers work with equal rates the departure process is stochastically maximized.

MSC classification

Type
Research Article
Copyright
Copyright © Applied Probability Trust 1997 

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References

[1] Chang, C. S. (1992) A new ordering for stochastic majorization: theory and applications. Adv. Appl. Prob. 24, 604634.Google Scholar
[2] Kamae, T., Krengel, U., O'Brien, G. L. (1977) Stochastic inequalities on partial ordered spaces. Ann. Prob. 5, 899912.Google Scholar
[3] Lehtonen, T. (1986) On ordering of tandem queues with exponential servers. J Appl. Prob. 23, 115129.Google Scholar
[4] Marshall, A. W. and Olkin, I. (1979) Inequalities: Theory of Majorization and its Applications. Academic Press, New York,Google Scholar
[5] Ross, S. M. (1983) Stochastic Processes. Wiley, New York.Google Scholar
[6] Stoyan, D. (1983) Comparison Methods for Queues and other Stochastic Models. Wiley, New York.Google Scholar
[7] Tsoucas, P. and Walrand, J. (1987) On the interchangeability and stochastic ordering of /M/1 queues in tandem. Adv. Appl. Prob. 19, 515520.Google Scholar