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Queueing Systems

, 58:239 | Cite as

On priority queues with impatient customers

  • Foad Iravani
  • Barış Balcıog̃luEmail author
Article

Abstract

In this paper, we study three different problems where one class of customers is given priority over the other class. In the first problem, a single server receives two classes of customers with general service time requirements and follows a preemptive-resume policy between them. Both classes are impatient and abandon the system if their wait time is longer than their exponentially distributed patience limits. In the second model, the low-priority class is assumed to be patient and the single server chooses the next customer to serve according to a non-preemptive priority policy in favor of the impatient customers. The third problem involves a multi-server system that can be used to analyze a call center offering a call-back option to its impatient customers. Here, customers requesting to be called back are considered to be the low-priority class. We obtain the steady-state performance measures of each class in the first two problems and those of the high-priority class in the third problem by exploiting the level crossing method. We furthermore adapt an algorithm from the literature to obtain the factorial moments of the low-priority queue length of the multi-server system exactly.

Keywords

Call centers M/GI/1+M queue Priority queues Impatient customers Level-crossing method Call-back 

Mathematics Subject Classification (2000)

60K25 68M20 90B22 

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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.UCLA Anderson School of ManagementLos AngelesUSA
  2. 2.Department of Mechanical and Industrial EngineeringUniversity of TorontoTorontoCanada

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