Join Zoom Meeting - ORCIBS SEMINAR -Amy R. Ward

Author: CASE
Time: 17:00

Passcode: ORCIBS

Date: 23 October 2020 -Friday
Time: 17:00- 19:00

Presenter: Amy R. Ward (University of Chicago)

Talk title:
Behavior‐Aware Queueing: The Finite-Buffer Setting with Many Strategic Servers

Abstract: Service system design is often informed by queueing theory, which helps system managers understand the impact of design decisions on performance. Traditional queueing theory assumes servers work at constant (possibly heterogeneous) rates, or speeds. That is reasonable in computer science and manufacturing contexts. However, the servers in service systems are people, and, in contrast to machines, their work speed can be influenced by the systemic incentives design decisions create. Workload is one such systemic incentive. Empirical research documents servers speeding up or slowing down depending both on how much work there is (i.e., the number of customers waiting) and amongst how many people that work is divided (i.e., the number of servers). We develop an analytical model to investigate how server work speed is affected by the system design decisions concerning (i) how many servers to staff, and (ii) whether and when to turn away customers.

We do this in the context of a finite‐buffer, many‐server queue (specifically, an M/M/N/k queue), except that we do not assume that service rates are exogeneous. Instead, we assume each server selfishly chooses her service rate in order to maximize an expected utility that captures an inherent trade‐off between idleness and effort cost in a fixed‐wage service system with no monetary incentives. Then, the service rates emerge as the solution to a noncooperative game. We provide results on equilibrium existence and uniqueness, and demonstrate non‐monotonic behavior. These results indicate that the commonly accepted rule of thumb that reducing workload decreases customer waiting can be flawed.

*** This is joint work with Raga Gopalakrishnan (Smith School of Business, Queen’s University) and Yueyang Zhong (Booth PhD Student).
*** Paper Link:

Short Speaker Bio: 
Amy R. Ward is the Rothman Family Professor of Operations Management, and Charles M. Harper Faculty Fellow, at the University of Chicago Booth School of Business.  She received her Ph.D. from Stanford University in 2001.  She has served as the chair of the Applied Probability Society (term 11/2016-11/2018), and as the Service Management Special Interest Group Chair for the Manufacturing & Service Operations Management Society (term 6/2017-6/2019).  She is currently the Stochastic Models co-Area Editor for the journal Operations Research.