Call centers are an increasingly important part of today's business world, employing millions
of agents across the globe and serving as a primary customer‐facing channel for firms in …

In a call center, there is a natural trade-off between minimizing customer wait time and fairly
dividing the workload among agents of different skill levels. The relevant control is the …

In summer of 2010, the first author (HL) visited the second author (XL) at Lanzhou University,
China, and chaired the dissertation defense for XL's two graduating doctoral students …

This paper focuses on monotonicity results for dynamic systems that take values in the
natural numbers or in more-dimensional lattices. The results are mostly formulated in terms …

We consider the problem of controlling a two-server Markovian queueing system with
heterogeneous servers. The servers are differentiated by their service rates and reliability …

We consider the problem of efficiently routing jobs that arrive into a central queue to a
system of heterogeneous servers. Unlike homogeneous systems, a threshold policy, that …

Motivated by call centers, we study large-scale service systems with homogeneous
impatient customers and heterogeneous servers; the servers differ with respect to their …

Traditionally, both researchers and practitioners rely on standard Erlang queueing models to
analyze call center operations. Going beyond such simple models has strong implications …

In this paper the problem of optimal control over a Markov queueing system with
heterogeneous servers and a joint queue is considered, which is also known in the literature …

The paper studies a controllable multi-server heterogeneous queueing system where
servers operate at different service rates without preemption, ie, the service times are …