Conflicts

[Dartacan]

I'm trying to generate the timetable for a school with two groups per year (12 groups total) but this year the program can't finish, it appears conflicts that can't solve. I change the distribution of the periods and subjects but , it's more or less the same... 225 of 234 and I can't advance. Any tip or recommendation!

[Liviu Lalescu]

Could you send me your file? If it is private, by email.

[Dartacan]

This is the file. I think I'm doing something wrong, and maybe I should change something but I don't know what to do... I have tried to change the periods of some subjects, but it's the same
Thank you in advance.

[Liviu Lalescu]

I tried to obtain a smaller impossible file. I attach one, in which I removed all time constraints without the break,  and teacher ANA-RELI. It seems impossible, it reaches max 232/234 fast and then stalls.

I will try some more.

I want to ask you if you know that an activity with duration > 1 cannot spread over a break. Otherwise, if you want to allow activities with duration 2 or 3 spread over a break, you need to simply remove the break constraint and decrease the number of hours per day from 10 to 9. If I do this on my attached file liviu3.fet it seems to work. If you want to do this on your file, don't forget to update the other "not available" constraints.

[Dartacan]

Thank you for your help. I have to think how to change something because we need "Ana-reli teacher". Maybe changing the periods of long subjects like lengua and mates, or dividing ciencias or EF  in 3 periods instead of 2.
I thought it was going to be easier

[Liviu Lalescu]

You can keep the teacher ANA RELI.

I tried something, I don't know if your school admits it, but it is the only way I could reach to a solution: I removed the break, and added a variable break for the students, using dummy activities with subject "pause students" which can be at 11:30 or 12:00. I attach the file and a solution. Unfortunately, I tried to add a variable pause for teachers but it did not work. This file is still difficult, I could only obtain one solution. It might be a starting point, if you add some constraints for the teachers.