Behind the holiday hustle: How industrial engineers help keep flights on time

The holidays bring a sharp reminder that a multitude of factors ranging from ice and snow to gate troubles and traffic build-ups can delay flights, but they also underscore the crucial behind-the-scenes role industrial engineers play in balancing it all.

While gate agents, flight attendants and pilots often serve the public face of an airline, industrial engineers are the unseen hand, using mathematical models to help figure out how to keep planes as on time as they can be.

Kevin Taaffe, now chair of the Department of Industrial Engineering at Clemson University, began his career in the thick of it, helping American Airlines manage scheduling as a consultant and senior manager for The SABRE Group.

Passengers and airlines alike have an interest in seeing planes with their wheels up, en route to their next destination, he said.

"Airlines want all their planes in the air, because that's when they're making money," Taaffe said. "You don't want to have too many of these backups in place with planes just sitting around. The solution, in simple terms, is that very complicated models have been built over decades for how to best route aircraft."

Taaffe took some time out from his own busy schedule in the lead-up to exam week to describe how industrial engineers keep planes flying and to offer a few travel tips.

How operations research keeps planes in the air

Taaffe said that industrial engineers who specialize in operations research help airlines build models that keep airlines on schedule as best they can.

Operations researchers design schedules that take into account such factors as how often flights serve cities and which aircraft to fly on various legs, while also accounting for potential pinch points such as air traffic and weather, he said.

"We find better ways to plan for when certain flights leave or when we can change the schedule from week to week, such that your schedule is more robust," Taaffe said. "But you can't get around the fact that you are going to have problems when there's bad weather or there's heavy air traffic."

Overbooking

Taaffe said any seat that isn't filled when the plane leaves is lost revenue, so airlines try to figure out how to best have the aircraft as full as can be when it leaves.

While many passengers book non-refundable tickets, some buy refundable tickets often at higher prices so they have the option of canceling at the last minute.

"Business travelers do this because they want the flexibility," Taaffe said. "If their plans change, they need a refundable fare. So, airlines overbook flights knowing that there are some passengers who have booked a flight, but they are not going to fly that day."

When there are more passengers than seats, airlines typically offer vouchers for future travel to passengers who agree to take a later flight.

Improving the boarding process

Taaffe said many studies have been conducted to find the best way for passengers to board a plane. They range from highly choreographed procedures to zoned boarding now popular with many airlines to the open-seat boarding ended by a major airline earlier this year.

So far, the quest for the perfect system remains elusive.

"There is a lot to study to try to figure out how you can make it a little faster," Taaffe said. "It seems like nobody's come up with it because there are so many side issues."

All it takes, for example, is one rear-seat passenger to store luggage in a mid-plane overhead bin to start disrupting a well-planned system, and those sorts of variabilities start to add up, Taaffe said.

Tips

Taaffe not only helped manage scheduling and terminal logistics for American Airlines, he is a well-seasoned air traveler, and he offered some tips for fellow passengers:

* To avoid getting bumped in a potential overbooking situation, it helps to have a seat assignment before heading to the airport. So, spending the extra money to lock down a seat could be worth it.

* It can be easy to go on autopilot at the airport and just follow the person in front of you. But those who pay attention to signage and look around might be able to split off from the pack and find a shorter line.

* Have patience: "If you plan to be on the road during rush hour, you expect there to be traffic delays," Taaffe said. "So when you go to the airport, don't expect everything to be on time during peak travel times, but especially during holiday traffic."