Constraint - Subject problems

[jefflai123]

Hi! Can I set a constraint of "Two subjects cannot on the same day" and "A subject is followed by another subject(on another day)? Because lecture class and tutorial classes cannot on the same day. Besides that, lecture should be taught before the tutorial classes. Please help. Thanks

[Volker Dirr]

please think twice about this problem. it is very similar to
http://lalescu.ro/liviu/fet/forum/index.php?topic=169.msg765#msg765
you you will have similar problems with holiday, illness, trips, ...

if you think your problem isn't effected by that, then you can use this workarounds:
"Two subjects cannot on the same day": Use min n day constraint with 100% weight to that activities.
"A subject is followed by another subject": instead of 1 hour for lecture and 1 hour for tutorial you can give them an activity with duration 2. so teachers and students don't need to change room and the teacher can also overrun or underrun the lecture lesson (a few minutes) without a problem, because the tutorial is consecutive.