So now I know why some of my flights have been cancelled. It could be something as simple as a scheduling problem when employees are not able to come into work.
I had always thought that there was something more serious at hand, like there were mechanical problems with the plane or that it was stranded at an airport because of poor weather.
Frankly, I think the scheduling conflict reason is almost inexcusable. Airlines should have backup plans, and double backup plans, to ensure that there is always the right amount of qualified personnel ready to step in if other people can’t show up for work.