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We consider a parallel server system that consists of several customer classes and server pools in parallel. We propose a
simple robust control policy to minimize the total linear holding and reneging costs. We show that this policy is asymptotically
optimal under the many-server heavy traffic regime for parallel server systems when the service times are only server pool
dependent and exponentially distributed.
J.G. Dai’s research supported in part by National Science Foundation grants CMMI-0727400 and CNS-0718701, and by an IBM Faculty
Award. 相似文献
2.
Ward Whitt 《Operations Research Letters》2005,33(4):363-372
Insight is provided into a previously developed M/M/s/r+M(n) approximation for the M/GI/s/r+GI queueing model by establishing fluid and diffusion limits for the approximating model. Fluid approximations for the two models are compared in the many-server efficiency-driven (overloaded) regime. The two fluid approximations do not coincide, but they are close. 相似文献
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In this paper, we consider the modeling and the inference of abandonment behavior in call centers. We present several time to event modeling strategies, develop Bayesian inference for posterior and predictive analyses, and discuss implications on call center staffing. Different family of distributions, piecewise time to abandonment models, and mixture models are introduced, and their posterior analysis with censored abandonment data is carried out using Markov chain Monte Carlo methods. We illustrate the implementation of the proposed models using real call center data, present additional insights that can be obtained from the Bayesian analysis, and discuss implications for different customer profiles. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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We analyze, using the optimal stopping theory, the entry-exit decision on a project, which takes time to be constructed and abandoned. We obtain the closed-form expressions of optimal start time of entry, optimal start time of exit, and the maximal expected present value of the project. In addition, we examine the effects of construction and abandonment periods on the optimal start times of entry and exit. 相似文献
6.
Inspired by service systems such as telephone call centers, we develop limit theorems for a large class of stochastic service
network models. They are a special family of nonstationary Markov processes where parameters like arrival and service rates,
routing topologies for the network, and the number of servers at a given node are all functions of time as well as the current
state of the system. Included in our modeling framework are networks of M
t
/M
t
/n
t
queues with abandonment and retrials. The asymptotic limiting regime that we explore for these networks has a natural interpretation
of scaling up the number of servers in response to a similar scaling up of the arrival rate for the customers. The individual
service rates, however, are not scaled. We employ the theory of strong approximations to obtain functional strong laws of
large numbers and functional central limit theorems for these networks. This gives us a tractable set of network fluid and
diffusion approximations. A common theme for service network models with features like many servers, priorities, or abandonment
is “non-smooth” state dependence that has not been covered systematically by previous work. We prove our central limit theorems
in the presence of this non-smoothness by using a new notion of derivative.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Consider the Geo/Geo/1 queue with impatient customers and let X reflect the patience distribution. We show that systems with a smaller patience distribution X in the convex-ordering sense give rise to fewer abandonments (due to impatience), irrespective of whether customers become patient when entering the service facility. 相似文献
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