Home | Business News | Browse by Publication | I | Industrial Engineer

Virtual queuing: could it be a reality for airports?

Article Excerpt
IF ELIGIBLE AIRLINE PASSENGERS WERE GIVEN A specific time window for arriving at the airport security checkpoint, would security lines, missed flights, and flight delays become things of the past? In fact, simulation modeling shows that "virtual queuing" would reduce checkpoint lines, enable passengers to spend almost no time waiting, and reduce total passenger wait time at many airports.

[ILLUSTRATION OMITTED]

A virtual queue is like an invisible line passengers wait in before entering a physical queue. A virtual queue at an airport security checkpoint would allow passengers to enter the checkpoint during a specific time window when more processing capacity is available. By shifting demand out of peak periods, the time that travelers spend waiting in physical queues could be reduced.

Background

Amusement parks typically have periods of both long and short lines during the day. Using virtual queuing, each participating guest is asked to enter a ride's queue at a specific time. These times are distributed so that demand is smoothed over the amusement park's operating hours. This way, the entire day is used, and demand is more optimally distributed. Portions of demand during the peak periods are moved to periods when demand is low. Because attractions can accommodate only a certain capacity, reducing demand during peak periods and moving it to times of excess capacity reduces the total wait time of all individuals in a queue.

Call centers that employ virtual queuing are also able to reduce total wait time. When the quantity of incoming calls reaches a predetermined threshold, callers are informed of the estimated wait time and offered a return call in the same amount of time. Like the amusement park example, demand is essentially distributed over a larger interval of time. Instead of callers waiting now, they can be processed in the future and wait virtually no time at all when more capacity is available.

Methods

Because flight schedules, airline operations, and demand levels vary across airports, security checkpoints at Indianapolis International Airport, Orlando International Airport, and Oakland International Airport were considered in a recent study.

To analyze the effects of virtual queuing at the selected checkpoints, this study used a discrete-event simulation in which each airport was analyzed with the following methods:

Simulation of the base case

Flight schedules. Each airport security checkpoint was first simulated without the presence of a virtual queue--the base case. Flight schedules for airlines whose passengers use the selected checkpoints were obtained from the Official Airline Guide for a peak day in the spring of 2004. The Indiana flight schedule has many morning departures followed by lighter activity throughout the day. The Orlando flight schedule has several peak departure periods (one of which contains large international carriers), each followed by periods of less activity. The Oakland flight schedule has a more consistent flight departure profile, with similarly sized aircraft leaving regularly throughout the day.

Earliness distributions. Next, assumptions regarding when passengers arrive before their flight departure time were established. The assumed earliness...