Hi,
I have the following Situation:
In my school there are 8 periodes every day. But One class only has lessons in the first 6 periodes. Because of this i set ConstraintStudentsSetNotAvailableTimes to periode 7 and 8 every day. Now there is one lesson in this class, which is allowed to take place in period 7 of two days, if there is no other solution. How can I achieve this?
Thank you
So the students have 31 hours per week?
Just delete the ConstraintStudentsSetNotAvailableTimes 7 and add a min hours per day = 6 for the students and maybe also a students must begin early constraint.
There may be many tricks possible. Maybe Volker's does not work, because you know the exact activity to be allowed late. But here is one trick that may work, if you have 0 gaps allowed for the students: constraint activities preferred time slots, all activities but that one (add a tag to them and the tag in the constraint), allowed in the first 6 slots of each day. Then preferred time slots for the particular activity, the first 6 slots of each day, some weight less than 100%.
Edited: One more thing I forgot: preferred time slots for that particular activity, 100%, first 7 hours of each day. This is not mandatory if the max gaps for students is 0 and early max beginnings at second hour for students is 0, but it helps (very little) FET towards a faster solution.
Of course there are a lot of possibilities to do that.
But like i wrote in other posts already i don't recommend to use less then 100% weight.
I recommend to use only 100% weight.
In your example you can also do following solution:
b) if you know which activity should be in period 7:
tag all activities with tag "1-6". add tag allowed times 1-6 period with 100% weight.
tag the one activity that should be late not with "1-6", only with "7". add tag allowed times only period 7 to "7" weight 100%.
or
c) if you wan't to define the period which take place at 7:
allow all period from 1-7.
add a subject "---"
add activity with subject "---", select the students, but no teachers. with min n day = 100%.
add constraint "---" must be in period 7 with 100%.
I bet variant c will be fastest, but it is not so "sweet". (it also might be a room problem if you use students home rooms, but i guess it won't be.)
Variant a) from my first post is in my opinion the "best", even if c) is a bit faster.
Thank you for your replies.
I tried Livius and it fits to my needs.
Thanks.
I edited a bit my post, please review it.