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Fluid limits of many-server queues with abandonments, general service and continuous patience time distributions
Walsh Zuñiga, Alexander - In: Stochastic Processes and their Applications 124 (2014) 3, pp. 1436-1468
This paper extends the works of Kang and Ramanan (2010) and Kaspi and Ramanan (2011), removing the hypothesis of absolute continuity of the service requirement and patience time distributions. We consider a many-server queueing system in which customers enter service in the order of arrival in a...
Persistent link: https://www.econbiz.de/10011064916
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Real-Time Delay Estimation in Overloaded Multiserver Queues with Abandonments
Ibrahim, Rouba; Whitt, Ward - In: Management Science 55 (2009) 10, pp. 1729-1742
in the overloaded GI/GI/s+GI multiserver queueing model, allowing customer abandonment. These delay estimates may be used … abandonment-time distribution to obtain new delay estimators that effectively cope with nonexponential abandonment …
Persistent link: https://www.econbiz.de/10009203791
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Service Interruptions in Large-Scale Service Systems
Pang, Guodong; Whitt, Ward - In: Management Science 55 (2009) 9, pp. 1499-1512
Large-scale service systems, where many servers respond to high demand, are appealing because they can provide great economy of scale, producing a high quality of service with high efficiency. Customer waiting times can be short, with a majority of customers served immediately upon arrival,...
Persistent link: https://www.econbiz.de/10009204276
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Responding to Unexpected Overloads in Large-Scale Service Systems
Perry, Ohad; Whitt, Ward - In: Management Science 55 (2009) 8, pp. 1353-1367
We consider how two networked large-scale service systems that normally operate separately, such as call centers, can help each other when one encounters an unexpected overload and is unable to immediately increase its own staffing. Our proposed control activates serving some customers from the...
Persistent link: https://www.econbiz.de/10009208550
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Fluid Models for Overloaded Multiclass Many-Server Queueing Systems with First-Come, First-Served Routing
Talreja, Rishi; Whitt, Ward - In: Management Science 54 (2008) 8, pp. 1513-1527
), each with many servers (housing units). Customer abandonment acts to keep the system stable, yielding a proper steady …
Persistent link: https://www.econbiz.de/10009218033
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When Promotions Meet Operations: Cross-Selling and Its Effect on Call Center Performance
Armony, Mor; Gurvich, Itai - In: Manufacturing & Service Operations Management 12 (2010) 3, pp. 470-488
We study cross-selling operations in call centers. The following questions are addressed: How many customer-service representatives are required (staffing), and when should cross-selling opportunities be exercised (control) in a way that will maximize the expected profit of the center while...
Persistent link: https://www.econbiz.de/10009218602
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Scheduling Flexible Servers with Convex Delay Costs in Many-Server Service Systems
Gurvich, Itay; Whitt, Ward - In: Manufacturing & Service Operations Management 11 (2009) 2, pp. 237-253
In a recent paper we introduced the queue-and-idleness ratio (QIR) family of routing rules for many-server service systems with multiple customer classes and server pools. A newly available server serves the customer from the head of the queue of the class (from among those the server is...
Persistent link: https://www.econbiz.de/10009218668
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Real-Time Delay Estimation Based on Delay History
Ibrahim, Rouba; Whitt, Ward - In: Manufacturing & Service Operations Management 11 (2009) 3, pp. 397-415
Motivated by interest in making delay announcements to arriving customers who must wait in call centers and related service systems, we study the performance of alternative real-time delay estimators based on recent customer delay experience. The main estimators considered are: (i) the delay of...
Persistent link: https://www.econbiz.de/10009218806
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Staffing of Time-Varying Queues to Achieve Time-Stable Performance
Feldman, Zohar; Mandelbaum, Avishai; Massey, William A.; … - In: Management Science 54 (2008) 2, pp. 324-338
customer abandonment (the + G). For Markovian M<sub>t</sub>/M/s<sub>t</sub> + M special cases, the ISA is shown to converge …, abandonment probabilities, and average waiting times--are stable as well. The ISA staffing and performance agree closely with the … abandonment. Although the ISA algorithm so far has only been extensively tested for M<sub>t</sub>/M/s<sub>t</sub> + M models, it …
Persistent link: https://www.econbiz.de/10009191191
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Adaptive Behavior of Impatient Customers in Tele-Queues: Theory and Empirical Support
Zohar, Ety; Mandelbaum, Avishai; Shimkin, Nahum - In: Management Science 48 (2002) 4, pp. 566-583
basic premise of this paper is that customers adapt their patience (modeled by an abandonment-time distribution) to their …
Persistent link: https://www.econbiz.de/10009218222