What’s the best way to board an airplane?

United Airlines will begin implementing a new boarding process for some economy passengers later this month, according to a recent company memo.

Here’s the process: Boarding window seat passengers first, then those sitting in the middle and aisle seats. Known in the industry as the Wilma (Window-Middle-Aisle), the process is intended to prevent passengers from having to get up at the aisle or middle seat when a later-appearing passenger needs to go to their window or middle seat.

United says this change could shave two minutes off its boarding process. But some airlines (including United) have previously implemented – then abandoned – this method, because it split up families and was chaotic for people boarding late. Which may be why United is allowing people on the same reservation (aka families) to board at the same time, regardless of where their seats are.

Zoom out: Airlines have long been experimenting with different boarding schemes to try to speed up the process. But, much like a small friend group with two wannabe alphas making plans, there’s much debate as to the best way forward.

Some favor a process like Southwest’s, with no assigned seats. Others, like astrophysicist Jason Steffen, advocate for what’s known as the Steffen Method.

• This process involves boarding passengers in very specific groups, so as to minimize the bottlenecks of Joe Schmo blocking the aisle to put his luggage in the overhead while his shirt rides up to show his beer belly. But critics say the method is overly complicated to implement (take a look for yourself), and doesn’t account for the various human issues that could (and will) arise.

Bottom line: Research shows boarding bottlenecks are the biggest detriment to airplane turnaround times, the WSJ reports. But if airlines can recoup enough minutes in each “turn,” they can squeeze in more flights – while making flying more pleasant for passengers at the same time.