Department of Systems Engineering and Engineering Management,

                    The Chinese University of Hong Kong


Ticket Queue Technology: Performance Evaluation and Service Improvement

Susan H. Xu (joint work with Long Gao and Jihong Ou)
Department of Supply Chain and Information Systems,
The Smeal College of Business,
The Pennsylvania State University,

Date : June 23, 2006 (Friday)

Time : 4:30 p.m. - 5:30 p.m.

Venue : Room 513, William M.W. Mong Engineering Building

(Engineering Building Complex Phase 2), CUHK

This paper considers a queue managed by numbered tickets: each customer is at
arrival issued a numbered ticket while the number being served is broadcast on
display. In the ticket queue customers estimate their expected waiting time
based on the difference between the ticket number issued and the number being
served and would desert the queue if the difference exceeds a tolerance level.
We construct a Markov chain model of the ticket queue and develop a two-step
procedure to compute its steady state distribution. As the exact computation
is exponentially time and memory space consuming, we propose an approximation
to the ticket queue by eliminating the states with negligible steady state
probabilities. A polynomial time algorithm is designed to compute the steady
state distribution for the approximate system and shown to be highly
effective. We then benchmark the balking probability of the ticket queue
against that of its counterpart physical queue in which customers have full
information of the queuing position. We show that the two systems would have
significantly different balking probabilities when customers' patience level
is low and the traffic intensity is high. We also propose an improvement to
the ticket queue by providing each customer with his expected waiting time
conditioned on his observed number difference; the improvement is shown to
raise the performance of the ticket queue on par with that of the physical

Susan H. Xu is Professor in the Department of Supply Chain and Information
Systems, Smeal College of Business, at Penn State University. She also serves
as the Chair of the Inter-college Dual Title Degree Graduate Program in
Operations Research at Penn State. She earned M.S and Ph.D. in Operations
Research and Statistics in Rensselaer Polytechnic Institute and has been on
the faculty of Penn State since 1987. Dr. Xu's current research interests
include stochastic modeling and optimization with applications in supply chain
and service systems, reliability modeling and stochastic comparisons. Dr. Xu
has published widely in leading professional journals. Her research has been
supported by NSF and other grants. Dr. Xu is Associated Editor of Operations
Research and Probability in Engineering and Inforamtional Sciences.


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Tel : 2609 8329
Email : yan@se.cuhk.edu.hk

For more information please

refer to http://www.se.cuhk.edu.hk/~seg5810/