preventing a student set(s) to use some rooms

[liquid]

At the primary school, there are students of age from 6 to 14. How to prevent allocating activities for older students to room where desks and chairs are too small for them? I don't think the set of home rooms is the most suitable solution for that issue. Indeed, I assigned some home rooms for classes 1-3 and it works. Is this the only solution?

[Liviu Lalescu]

Preferred (and maybe home rooms) is the way. You can add 100% preferred from all old students activities to all big chair rooms. This will be in addition to usual preferred rooms.

[liquid]

I thought of "preferred rooms" for a student's set or sets. Now, we do have preferred room(s) for an activity and home room(s) for students but we do not have preferred rooms for students. I'm not sure what exactly program does when it must satisfy constraint of home room. I imagine it has the effect that students rather seldom move from home room. If you assign some rooms as home ones for a student set it negates in a way the sense of home room constraint. I cannot set preferred room for an activity because the same one is present for younger and older students; splitting an activity into two: e.g. English language for younger and older students, is a bit artificial.
It may be a kind of suggestion if you agree with my point of view.

[Liviu Lalescu]

I am sorry, but I do not understand. Maybe Volker can understand better.

The space constraints, as preferred and home, were chosen after long thinking. I could not make preferred rooms for students, because of many reasons, which I don't recall now (maybe they are somewhere here on the forum). Oh - I found it: http://lalescu.ro/liviu/fet/forum/index.php?topic=628.msg3828#msg3828

Maybe an easy way would be to add an activity tag to some activities, then use activity tag preferred room(s).

I really don't understand what you mean by splitting. You mean you want an activity to occupy two rooms? This is impossible in FET (and too difficult to make), so you need to use tricks (like dummy same starting time activities, or divide the students).

[Volker Dirr]

I don't see the problem. Especialy if you have rooms with different chairs (for short and tall kids) the roomS constraints work fine.
As Liviu said: Using an activity tag for short and on other activity tag for tall kids is possible variant.
Please also read http://www.timetabling.de/manual/FET-manual.en.html#id_46

[liquid]

Maybe an easy way would be to add an activity tag to some activities, then use activity tag preferred room(s).

I think it's the best solution for that case. I'm going to use it in this way:
a tag will be named "subject for older students" (or so) and when I'm planning an activity with given subject for older students I'll use this tag and for younger ones - I won't. Of course, I'm going to set preferred room for subject+tag as well.

I really don't understand what you mean by splitting. You mean you want an activity to occupy two rooms? This is impossible in FET (and too difficult to make), so you need to use tricks (like dummy same starting time activities, or divide the students).

I'm sorry, I thought of subject, not of activity; and not exactly of splitting but introducing a new subject for older. Forget, above solution seems to me feasible and working as my intention.
Thanks a lot.

[liquid]

One more question:
What's the precedence of constraints

• subject has preferred set of rooms
• activity tag has preferred set of rooms?

[Liviu Lalescu]

Intersect sets of rooms (if weights are 100%). Otherwise, process them in turn.

All constraints are respected, only home rooms are not respected if a preferred room is respected.