Assigning Room

[Svnty7]

I have a newbie question.  When I generate a timetable, a schedule is created for the teachers, but no activities are being assigned room.

Thank you.

[Liviu Lalescu]

You need to add some space constraints, otherwise FET considers that the room of each activity may be unspecified, and chooses this shortcut.

[Christian Kemmer]

I have a similar question:

I have lots of activities, which do not need a certain room, and FET does not provide "all-subactivities-of-an-activity-same-room"-constraint. So I do not ad space constraints for those activities and assign the rooms manually after the plan has been generated.

How can I add these rooms to the timetable produced by FET?

[Liviu Lalescu]

I have a similar question:

I have lots of activities, which do not need a certain room, and FET does not provide "all-subactivities-of-an-activity-same-room"-constraint. So I do not ad space constraints for those activities and assign the rooms manually after the plan has been generated.

How can I add these rooms to the timetable produced by FET?

Add preferred room space constraints, for each activity, or for special activity tags.

[Christian Kemmer]

Okay, but I have to change rooms manually afterwards to guarantee that all subactivities of an activity are placed in the same room. How can I do this after (!) generation of a time table?

Example:

I only have rooms r1, r2, and r3.
r1 is free: Monday hour 1 and Tuesday hour 2
r2 is free: Monday hour 1 and Tuesday hour 3
r3 is free: Monday hour 2 and Tuesday hour 3

FET should place activities a1, a2 and a3 (all consisting of two sub activities) in rooms r1, r2, r3. I only see two possibilities:
a) I add a room-constraint to all activities, so that each activity has only one room
--> FET has only one possibility to place these activities. This is not, what I want to have.
b) I add a room-constraint to all activities, so that each activity can be placed in one of these three rooms.
--> FET has more possibilities (3!=6) to place these actitivities, but one activity may be placed in r1 (first sub activity) and r2 (second sub actitivity), so I have to correct this manually by changing rooms after generation.

My question in this example: How can I change the rooms in a generated time table?

[Liviu Lalescu]

I already knew your problem, my idea was to add/modify space constraints after you generate a timetable and fix all activities in time and maybe in space. See space constraints: each activity locked in space will have attached a not permanently locked preferred room. Change this constraint, or add one if an activity is not locked in space. Then generate again.

Please let me know if this solves your problem.

[Christian Kemmer]

I have followed your advice. It works, but ist is time consuming. It took me about twenty hours to add all rooms. I did the following:
1. Print time table for each FET-year, which has activities without rooms.
2. For each activity, choose one room, consider room capacity and look whether a room is free for all sub activities of one activity.
3. Add space constraints in FET and generate again.
4. For each of the remaining activities, try to place its subactivities in any room, not necessary the same.
5. This worked for about 80%-90% of all activities. Afterwards, I had no free rooms for the remaining activities and I had to move those or other activities, to get enough free rooms. (We are extremly short on rooms in our school, if there are too much activities at the same time, especially activities lasting longer than one hour.)
Especially 5.) took much time.
So I really would like to have an "all-subactivities-of-an-activity-same-room". I would use that with an weight of only "95%" or something like that, because there might be situations where this constraint cannot be fullfilled.

[Liviu Lalescu]

Sorry, I cannot add the "activities same room" constraint.

Maybe you could invent some tricks.

[Liviu Lalescu]

So I really would like to have an "all-subactivities-of-an-activity-same-room". I would use that with an weight of only "95%" or something like that, because there might be situations where this constraint cannot be fullfilled.

After thinking for a while, this constraint may be possible. But a decent treatment would be only with 100% weight. Please tell me if you would consider this useful.

Please see also: http://lalescu.ro/liviu/fet/forum/index.php?topic=684.0

[Liviu Lalescu]

See discussion on link above. I think that such a constraint is not needed, because, as lalloso said, if a user wants the same room for a students set, then he may decide exactly which room.

[Christian Kemmer]

I read that discussion. I would prefer to have this constraint. If only "100%" is possible, I have to decide, which activities get the constraint and which not, but I really would use it.

Let me describe our situation in more detail:
In our school, about 50%-60% of all pupils have "classes" with a "home room". These are twenty rooms. The remaining 40%-50% of our pupils do not have "home rooms" and only nine non-special-rooms (The labs, the gym, ...) remain free. So we need lots of the other pupils home rooms, when those are free (because pupils are in the gym, in the lab, in the music-room, ...) to place the activities of the remaining pupils.
At the moment, I have two possibilities:
a) Let FET place all activities in one room.
b) Let FET only place the first 60% in a (home) room, place the remaining 40% by hand.

If I choose a), lots of courses with more then one hour (in our case 2+1, 2+1+1, and 2+2+1 hours for the sub activities) get different rooms for the sub activities. So I have to change rooms manually, if possible.
If I choose b), I have to place alle the rooms manually. This seems to be more work than a), but I easily see which activities have to be placed (those without rooms) and I can place difficult activities (i.e. those with most hours, most students, most parallel activities) first.

If I could use that constraint with 100%, I would choose some activites of the remaining 40%-50% and let FET place them, so my effort for placing activities manually, would be reduced.

So, if it is possible, I would ask you, to consider implementing this constraint with an weight of "100%" again.

Best regards,

Christian Kemmer

[Liviu Lalescu]

I understood your request, but there are some serious reasons not to add a constraint activities same room:

1) I proposed this constraint to the forum. I think George misunderstood this constraint, thinking it refers to simultaneous activities, and the room could host more activities at the same time. If more users misunderstand, they'll get impossible timetables and no clue on what is wrong.

2) People will overuse the constraint and get impossible timetables without a clue on what is wrong.

3) Home rooms, preferred rooms, unspecified room: you might add this constraint to some activities with preferred room 90% and home room 90%. Then, FET will request that either all activities are in the preferred room, XOR (exclusive or) in the home room, XOR in an unspecified room. Again, situations might be impossible and the timetable impossible without a clue.

4) Even in your situation, you may get impossible timetables without a clue on what is wrong.

I might be able to help you with a custom version and see how it looks like and think about adding the constraint to the official.

[Volker Dirr]

i think your argument 1), 2) and 4) are only 2 week arguments. With that arguements many other constraints must be deleted from fet, because also several other constraints are not clear to some users (just compare the forum) and also with most of them you can "get impossible timetables without a clue on what is wrong".

i am not sure about your arguement 3). But like you know: i always suggest to use only 100% weight.

my favorite variant is currently still this:
don't add that as a "new" constraint. (because it is not very userfriendly to use it. a user like Mr Kemmer must add to many of that constraints).
in my opinion it should be an option in the min n day costraint similar to the "consecutive"-option. That is as flexible as a "new" constraint, but it will be much easier to work with it as a user.

i know you don't like "mixing"-constraints, but:
a) you already mix that constraint (with "consecutive"-option as "timeoption", so why not mixing with "same room"-option as "roomoption".)
b) in my opinion it will be the most userfriendly implementation of that constraint.

[Volker Dirr]

I forgot to say:
That constraint is also not as critical as you think. i know how Mr. Kemmer is doing his activity planing in the higher years, so i also know that he can see a lot of activities that might be/must be at the same time. So he can add that room constraints to them without any high risk. it is totaly uncritical to the most activities. Just a few of them might be critical.
he want to use the constraint to the upper years as something similar to the home-rooms in the lower years.
But he can't use the home-rooms constraints. But adding/thinking about the "new constraints" is only as critical/easy as thinking about home-rooms in the lower years.

[Liviu Lalescu]

Reviving a new topic: starting with FET-5.18.0 there is a new constraint activities occupy max different rooms and starting with FET-5.20.0 there is a new constraint activities same room if consecutive.