Why would there be so many changes? Do they seem legitimate, or more like they are trying to justify spending money on the scheduling system and playing with the new toy?
It is more related to sick leave and general scarcity of teachers. I guess before the existence of timetable apps they were better in finding creative ways around those changes.
In my experience, teacher absences just meant substitutes, another teacher swapping over / handling two classes, or an impromptu class period spent watching something on tv.
I'm not sure that was much better than just telling the students in advance when you know a schedule will change and sending them to the library to study or etc.
