[kqr]

As long as the planes don't leave, the airline will know exactly where staff and equipment are: right where they were when the system broke. Once things get moving it becomes really complicated to figure out where everything is again.

During previous similar outages it has taken days to track down staff and equipment once the systems are up again. During this time delays and cancellations continue. It's possible the system is much faster to bootstrap given correct locations of things from the start.