Re: How to put activities in certain rooms?

[Volker Dirr]

Maybe you can also ease the problem if the biology teacher also teach his other subjects in the biology lab.
Maybe similar with a physics teacher.

[Chafik Graiguer]

Maybe you can also ease the problem if the biology teacher also teach his other subjects in the biology lab.
Maybe similar with a physics teacher.

unfortunatly Yes !!  that is already the case

[Chafik Graiguer]

I think that with this two hints:
1-

Nevertheless if you want to avoid that teacher change rooms you can give at least 10 teachers a home room. so that 10 teacher will never change the room.
maybe you can see some other teachers, that can share a room with one of the 10 privileged teachers.
so of course there are still a few teachers left.

2-

I was reading and the building changes just passed through my mind. Yes, alfaromeo is right, add a building for each room and use max building changes per day for teachers. I think it should work.

room problem is solved
Now I am facing other problem described here :
http://lalescu.ro/liviu/fet/forum/index.php?topic=209.0

[Chafik Graiguer]

I was optimistic about room assignement
Yes, I have a very good working timetable, but room assignement for teachers is a little bit random,
Teacher has to change room 1 or two or 3 times in a day !!
unfortunatly, no hints works for me
with the building hints ( maxximum change of building per day for all teachers=0) , FET was unable to go beyond 315 out of 323 placed activities

in other words, FET was about to generate the perfect timetable
only 8 remaining  activities need to be placed  
I am quite sure that if a teacher T1 was given a room R1 on first timeslot, this room will be available for him during the next 3 timeslots
So why,at second timeslot, this room R1 was given to teacher T2 , while the room R2, the T2 had on first period, is given to T1 !!?

[Liviu Lalescu]

Please try to let FET some more to calculate, maybe it can solve it (let it one hour or more).

Also, please try with max building changes per day 1, maybe you can obtain this way a timetable.

FET can switch rooms for teachers if you don't constrain it (by max building changes).

Please send me your latest file, I'll try from home to see what I can do.

Maybe you can lower teachers max days per week (increase days or remove constraints).

[Chafik Graiguer]

Please try to let FET some more to calculate, maybe it can solve it (let it one hour or more).
.

Ok I will give it more time

Also, please try with max building changes per day 1, maybe you can obtain this way a timetable.
.

But I already have a timetable !!!
this "room assignnement" issue is the sole minor problem I still have

The other problem is that I dont know how to diagnose those remaining 8 activities with options:
- see initial order of placing theactivities....
- see difficult activities without stopping simulation...

EDIT: with
maximum building change per xweek for all teacher ---> 2
FET is now able to reach : 320 out of 323 placed activities  !!!

[Liviu Lalescu]

I meant to make max building changes per day 1 and obtain a better timetable than with no max building constraints.

I think you cannot get help from the impossible activities dialog or initial placing of activities. It is just that your timetable data might be too constrained. Try to lower some constraints (max building changes 1 instead of 0 or weaker max days per week for teachers).

I'll check your latest file. It will take about 30 minutes, I am now compiling your variant of FET (I removed it from my hard disk because I don't want to mix versions accidentally).

[Liviu Lalescu]

I tried for your sample with max building changes per day for all teachers 1, and it solved in under 2 minutes. I am attaching the file and data+timetable.

Please let me know.

LATER EDIT: It does not solve for max building changes 0 for teachers, I let it 30 minutes. It is maybe impossible. You need to reduce some constraints. Maybe put for more important teachers max building changes 0 and rest 1 and try again

[Chafik Graiguer]

this will need same trial and error !!
I simply deleted the maximum building change constraint !!
Then, I set :
maximum gaps per wek for all teachers ---> 1
FET solve it very quickly
there was only a total of 2 gaps
one for teacher fr3
and another one for teacher eng1

the great good news is that every teacher from the first 13 teachers in the list has a uniqur room in a given day
only the last 5 teachers in the list have to change rooms in some days !!!

So it is a  fair deal : paying 2 gaps to have a homogenous room assignement !!!

my question: why FET did it for 13 rteachers without any building constraint  !!!!!?

[Liviu Lalescu]

this will need same trial and error !!
I simply deleted the maximum building change constraint !!
Then, I set :
maximum gaps per wek for all teachers ---> 1
FET solve it very quickly
there was only a total of 2 gaps
one for teacher fr3
and another one for teacher eng1

the most good news is that every teacher from the first 13 teachers in the list has a uniqur room in a given day
only the last 5 teachers in the list have to change rooms in some days !!!

So it is a  fair deal : paying 2 gaps to have a homogenous room assignement !!!

my question: why FET did it for 13 rteachers without any building constraint  !!!!!?

You obtained this by chance or you didn't remove all buildings changes constraints.

You can leave max gaps 1 per week for teachers and add buildings changes 0 for teachers and see if you get a timetable.

[Chafik Graiguer]

You obtained this by chance or you didn't remove all buildings changes constraints.

You can leave max gaps 1 per week for teachers and add buildings changes 0 for teachers and see if you get a timetable.

sorry
I did a mistake
yes building constraint is still in place only for the ........ lucky 13 teachers            

[Liviu Lalescu]

I saw in the file that you set max gaps per week for students 1, is that all right for your data? I think you need 0.

Also, you added teachers max gaps 0, which means all teachers have maximum gaps 0. The two other teachers which get max gaps 1 are also constrained to have 0 gaps, so the 1 gap is useless constraint. I cannot change that, although I would like it, but some people might make mistakes. And also max gaps for teachers means that all the teachers should have these max gaps, no matter the other constraints.

LATER EDIT: So, please remove the max gaps constraints for all teachers and add for each teacher the required max gaps with teacher max gaps.

[Chafik Graiguer]

I saw in the file that you set max gaps per week for students 1, is that all right for your data? I think you need 0.

.

Yes. this was another mistake  
I was in a hurry because I want to finish the timetable before tomorrow afternoon !!!

[Chafik Graiguer]

please take a look et the attached file
I am not sure, but I think  I solve it in a simple way
we have 20 teaches and 10 rooms
I set every two teachers to one home room !!
A little problem: the two teachers cant work at the same time.they have to work on dfferent days. but this doenot rise any problem right now

[Liviu Lalescu]

I cannot check it for now, because I again removed the alfaromeo FET version from my hard disk.

But if you say that it works OK, I don't need to check it.

I am a little bit puzzled, because if it works like this it should also work with teachers max building changes per day = 0. Maybe you lowered other constraints or, in the variant with max building changes, you specified less preferred rooms.

I saw your newest file. You have teachers max gaps per day = 0, this means that your teachers cannot have any gaps per day or per week. Please be more careful.