Max buildings changes per week for all students

[Omar Ben Ali]

Hi
I set the "max building changes per week for all students" to 0. We have 4 rooms in buiding A and 14 rooms in building B. I understand that it is impossible for fet to generate a timetable with this constraint.
As you know, students has activities in 4 periods H1 , H2, H3 and H4 with a short break 10 mn between H2 and H3. So students may changing buildings during this short break.
I propose a new constraint to allow buidings change between a specified paire of periods H2 and H4.
Thanks

[Volker Dirr]

That is already possible today.

You must do this:

1. go to fet -> data -> days and hours -> hours
add a new period between H2 und H3 (maybe call it "break")

2. go to fet -> data -> time constraints -> misc -> break times
add a new break. Set a break constraint for all the new hours (the whole period) (see point 1).

3. go to fet-> data -> space constraints -> students -> min gaps between building changes for all students
add a constraint with 1 gap (that will be the new break) with 100%

[Liviu Lalescu]

Volker, I think this works if he has students max gaps per week = 0.

Otherwise, I could try to make you a custom version. Let me know.

[Volker Dirr]

If the students are fast enough to change the buildings in a 10 minutes break, then they will be also fast enough to change the buildings during a whole lesson (since i bet a lesson is much longer than the break).
So it will work also if students have got no max gaps constraint.

The problem might be special rooms like gym or labs. (i don't know if that school have got those rooms/activities)
But if those rooms are used only for an single hour and all other activities are in the other building, then it will be impossible if students gave got a full timetable and no gaps allowed. In that case you need a building swap. I think the only trick to avoid impossible timetables is to place the special rooms NOT into a building. So in that cases a building swap might still be necessary.

[Omar Ben Ali]

Thank you for your replies.
I will try the Volker suggestion but i think a new constraint will be useful for many users.

[Liviu Lalescu]

I propose a new constraint to allow buidings change between a specified paire of periods H2 and H4.

Do you mean between H2 and H3?

I will try the Volker suggestion but i think a new constraint will be useful for many users.

I am sorry, but I prefer not to add such a customization in the official version. It is too particular. I do not know how to specify the exact periods.

I am ready to talk some more about this.

Let me know if you want the customization in a special version just for you.

[Omar Ben Ali]

I propose a new constraint to allow buidings change between a specified paire of periods H2 and H4.

Do you mean between H2 and H3?

Sorry, yes i mean between H2 and H3.

I am sorry, but I prefer not to add such a customization in the official version. It is too particular. I do not know how to specify the exact periods.

There is a short break 10mn between H2 and H3 in the morning and in the afternoon and such a customization will not be useful between H1 and H2 or between H3 and H4. The only possible pairs is (H2,H3).

I am ready to talk some more about this.
Let me know if you want the customization in a special version just for you.

Many thanks.
That's very kind of you

[Liviu Lalescu]

Many thanks.
That's very kind of you

I added the custom version. Please get it from: https://lalescu.ro/liviu/fet/download/custom/omar-ben-ali/

It might have bugs, I am not 100% sure on my code.

[Omar Ben Ali]

Many thanks.
That's very kind of you

I added the custom version. Please get it from: https://lalescu.ro/liviu/fet/download/custom/omar-ben-ali/

It might have bugs, I am not 100% sure on my code.

thank you.
but 5. 37.2 is the official version of fet and i am using the moroccan version !

[Omar Ben Ali]

I used this custom version for a file_data_and_timetable.fet  obtained by  fet.5.27.3-morocoo33 . I used the constraint "max building changes per day for a students set". it seems working.
But when i used the constraint for all students, fet can't solve the problem. Maybe  because  timetables were allready obtained before.

[Liviu Lalescu]

I am sorry, my mistake! I did not see that this topic is on the Morocco board. Lucky the changes are not many.

Please get again from the same link: https://lalescu.ro/liviu/fet/download/custom/omar-ben-ali/

I think you need to generate from the start, with a new empty (not locked) timetable.

[Omar Ben Ali]

I am sorry, my mistake! I did not see that this topic is on the Morocco board. Lucky the changes are not many.

Please get again from the same link: https://lalescu.ro/liviu/fet/download/custom/omar-ben-ali/

I think you need to generate from the start, with a new empty (not locked) timetable.

Good job , this custom version seems to work well.
with the constraint "Max buildings changes per week for all students"=0, fet seems ignores all changes between the periods H2 and H3.
Thank you very much.

[Liviu Lalescu]

You are welcome!