Southwest flight upheaval a 'system failure,' U.S. says

the flight planning and crew scheduling software was not connected. the flight planning software assumed the crews made their flight, and when they didn't the crews had to call and get the flight planning software manually updated.

the call center to handle the manual updates got overloaded, the crews were put on hold for long periods of time, the crews 'timed out' due to all of the over work, the planning fell apart.

this was a lack of investment in their infrastructure and running things on a shoestring.

100% management's fault, as all of these problems were well known but never addressed.