Graduate Seminar: Jianzhe Luo & Alex Mills (The University of North Carolina at Chapel Hill)

A Tandem Queueing Model of Direct & Indirect Waiting in an Appointment System

Jianzhe Luo (The University of North Carolina at Chapel Hill)

We develop a useful queueing model for an appointment system which consists of an appointment queue and a service queue. We propose a Decoupled-Two-Queue model in which the appointment delay customers encounter in the appointment queue affects their show-up probability at the service station. We obtain some important performance measures of interest and manage to solve the optimization problem that aims to minimize the server's long-run average idle time while keeping customer long-run average waiting times in both queues below given levels.  This is a joint work with Vidyadhar Kulkarni and Serhan Ziya.

Mass-Casualty Triage Strategies

Alex Mills (The University of North Carolina at Chapel Hill)

A mass-casualty incident occurs when the number of injured patients overwhelms the resources available to take care of them. 
In such incidents, the process of sorting and prioritizing patients, known as triage, is especially important.  The most widely used standard for mass-casualty triage, START, relies on a fixed priority ordering among the different classes of patients, and does not explicitly consider resource limitations or the patients' probabilities of survival. We construct a fluid model of patient triage in a mass-casualty incident that incorporates these factors and characterize its optimal policy. We use this characterization to obtain useful insights about the type of simple policies that have a good chance to perform well in practice, and we demonstrate how one could develop such a policy. Using a realistic simulation model and data from emergency medicine literature, we show that the policy we developed based on our fluid formulation outperforms START in all scenarios considered — sometimes substantially.  This is a joint work with Nilay Tanik Argon and Serhan Ziya.

Refreshments will be served at 3:30pm in the 3rd floor lobby of Hanes Hall