activities max simultaneous?

[Benahmed Abdelkrim]

 I think this constraint merit to shed on it more light.
when? and how? use this constraint.
what are the impacts on speed generation of tables?

[Liviu Lalescu]

Suppose each activity has a single teacher.

If you have in total 10 teachers and in each slot you want 2 free teachers for supervision of the school, add a constraint with all slots selected, all the activities of the timetable, and max simultaneous = 10 - 2 = 8.

If there are some activities with more teachers, you need to use dummy activities, as explained if you press Help in the constraint's dialog.

Simply, in a slot with X there must be at most n activities from those selected.

I did my best to optimize the speed.

[Benahmed Abdelkrim]

please can we have a example.fet to better understand?

[Liviu Lalescu]

See the last time constraint. The number of teachers is 33. The max occupied in each slot is 31, so this constraint should ensure that at each moment there are at least two free teachers (which you can see in the Teachers' Free Periods timetable). But this thing is not exactly true, because there are activities with more teachers in this sample, so you need to use dummy activities as explained in the Help, if you want a perfect solution.

[Benahmed Abdelkrim]

thank you very much, now it's clear.