Hello Sir:
What should I do if I want to minimum the sum of all teacher's gaps?
Looking forward to your reply.
There is no such rule.
In my opinion it is unneeded, since it is not fair.
Because it mean all full time teachers might get 0 gaps, nearly all part time teachers get 10 gaps and one part time teacher even get 20 gaps.
So this is a pretty unfair constraint.
You should lower the number of gaps far all teachers similar to be fair.
Of course it sound maybe fair if you can sove the timetable with 2 gaps, but it look like 1 gap per week is too difficult. So you want to add also your request.
But i think also this is unfair.
You might add different rules for part time and full time tachers to be more fair.
You might add exceptions for staff members and trainee teachers to be more fair (you can care about the last very easy by giving them pseudo activities).
If you don't want to do it that way i recommend to set the impossible number of gaps (which looks impossible in the first tests) and restart generating automatoically after x minutes. In many difficult datasets you can get much faster a result if you do it that way instead of generating without a time limit.
supplement:
hmm... it might be useful if you have got a school where max 1 gap per week is possible, but 0 gaps per week are impossible.
Also in that variant i suggest to do exceptions for staff, trainee, ... first.
I fear Liviu haven't got time to think about this problem in the next weeks. So let us maybe think about this later once again.
Got it. Thank you for your suggestion ;D
I am sorry, but this is too difficult.