HOW FAIR IS YOUR QUEUE
Speaker: Hanoch Levy*,
One of the major reasons for using queueing
mechanisms is the wish to provide fairness in treatment to the customers
of a system. Recent studies show that
fairness in queues is indeed very important to humans, perhaps not less than
the waiting itself. Nonetheless, Queueing Theory has hardly dealt
with this issue, and an agreed upon measure of queueing fairness does not
exist. Our objective is to understand
queue fairness and develop a fairness measure that can be used by theorists and
practitioners to evaluate the fairness level (and thus quality) of their
system.
One of the major obstacles in attempting
to address queue fairness is the need to deal with two orthogonal physical
properties, seniority and service requirement, to address the
trade-off between them and to create a metrics that is sensitive to both in a
consistent and intuitive way.
We propose RAQFM, a Resource
Allocation Queueing Fairness Measure, which focuses on the system resources and
on how fairly they are allocated to the various customers. RAQFM is unique in
accounting for the intricate relations between customers within the queue and
is sensitive to both seniority and service requirements. RAQFM also yields
itself to analysis via common queueing-theory machinery, and thus can be used
in theoretical studies as well as practical applications evaluating queue
fairness. Lastly, RAQFM can bridge a major conceptual gap between the beliefs
of ordinary persons (FCFS is more fair than LCFS) and recent queueing theoretic
results (LCFS more fair than FCFS). We analyze RAQFM, demonstrate its
properties and review its application in a variety of queueing systems.
*Joint work with: Benjamin Avi-Itzhak and
David Raz.