| A key point is how they do routing - https://www.ajot.com/news/southwest-air-faces-gridlock-with-... > Unlike competitors that use a so-called hub-and-spoke system to funnel passengers to large airports, Southwest is focused on point-to-point service, flying the same aircraft — Boeing Co. 737s — on trips that may hopscotch around the US. With a hub and spoke system, all the planes go from A to HUB and then from the HUB to somewhere. If the route A-HUB gets saturated, they can put more planes on that, and those planes can always be found at the HUB. This applies to crews too. You'll have something that looks like this: https://www.airlineroutemaps.com/maps/Delta_Air_Lines/North_... This comes at the cost of having oversupply at some spots and its harder to offer the "ideal" routes as everyone needs to transfer to another plane with a layover somewhere... and your baggage is more likely to get lost. There's a bit not to like as a passenger on such an airline unless it's a nice one leg route - but then who wants to fly to Detroit? Southwest is different - they go from anywhere they want to anywhere they want with non-stop flights and picking the most lucrative routes they can. This lowers the effective cost per flight and are likely non-stop flights. Everything that a customer wants. Southwest routes from 2001 https://www.flickr.com/photos/erussell1984/15863298679 - you can see the lack of hubs there. This is done through some crafty constraint programming to try to make sure that all the capacity is where it needs to be when it needs to be there. However, when the capacity hits "holidays - everything is at max", along with "big storm prevents flights from going to where they need to be for the next leg" this system breaks down and planes and crews are out of position or need to sleep. Their software was able to handle this constraint system when it was a smaller company with fewer routes - there were fewer constraints. The "reset" is not "shut down the computers and start them back up" but rather "let all the crews get their required sleep and then go to the spot where they need to be in order to handle the load - not where they currently are (out of position)". Hypothetically, this is solvable if you have enough compute... but that's a lot of compute that needs to be recomputed each time something changes (weather, crew gets sick, passenger load changes) and that ends up being impractical and expensive. --- Related reading: NYT - What Caused the Chaos at Southwest : https://www.nytimes.com/2022/12/28/travel/southwest-airlines... WSJ - How Southwest Airlines Melted Down : https://www.wsj.com/articles/southwest-airlines-melting-down... --- https://news.ycombinator.com/item?id=34165791 |