Under a boarding method suggested by R. John Milne, an assistant professor of engineering management, passengers are seated from the back of the plane to the front and from the windows to the aisles.

Milne adds another wrinkle: He also suggests airlines seat passengers in a way that spreads the carry-on luggage throughout the plane. In each row, the airline would seat at least one passenger with two bags, one passenger with one bag and one passenger with no bags.

“So now you don’t have delays where people are trying to cram all their luggage in the overhead compartment,” Milne said in an interview.

Milne’s study found that this boarding method can cut seating time by an average of 3% compared with a back-to-front boarding scheme. For a large carrier such as Delta Air Lines, the process could save as much as $10 million a year, according to his study, published this month in the Journal of Air Transport Management.