New constraint: A set of activities are in the same room in selected time slots

[Benahmed Abdelkrim]

Good morning!
I have a suggestion if you allow;
Add space constraint:
A set of activities are in the same room in selected time slots.

This constraint is very useful in many cases, especially if the user chooses to have certain activities in the same room during certain time slots.

What do you think?

[Volker Dirr]

hmm.. why only in selected time slots (so why not always?). Can you give an example where that is needed?

[Benahmed Abdelkrim]

hmm.. why only in selected time slots (so why not always?). Can you give an example where that is needed?

Well I'll give an example:
    Suppose we have a group of students who do not have a fixed room.
So we will have to move from one room to another when these rooms are free.

If we have a break  time, there is no problem. We will use the space constraint that makes the room change during the break time. (min gaps between building changes)

    But to say that during periods of time the school can do away with the break because of the small number of hours 2 or 3, as in Algeria and in other countries (perhaps) especially in the afternoon. In this case, the use of the  space constraint mentioned above is of no use, especially in the Moroccan and Algerian versions.

   The student group moves to another room that may cause discomfort to neighboring groups and teachers as well, so it is best to keep them in the same room during the specified period.

I suppose I was clear in the explanation.

[bachiri401]

for moving classes (classes which don't have rooms) we always find a problem in the first hour of the afternoon because we have the constraint all students start from the first hour so all the rooms will be occupied the first hour and the laboratories wont be used most of the time in the afternoon

[Benahmed Abdelkrim]

for moving classes (classes which don't have rooms) we always find a problem in the first hour of the afternoon because we have the constraint all students start from the first hour so all the rooms will be occupied the first hour and the laboratories wont be used most of the time in the afternoon

I do not use this constraint because it is strong, Especially in difficult timetables like the tables I make, to make it easy and make them solvable in a "short time" (less than 24 hours).

[bachiri401]

but for a school gate to be opened two times in the morning and two times in the afternnon this will create lack of displine and also the first hours are always the best for grasping knowledge

[Volker Dirr]

I suppose I was clear in the explanation.
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Nice idea.

[Benahmed Abdelkrim]

There may be no need to add the proposed constraint. Because I have found a smart trick to make the break time available in the afternoon for all students and teachers.
Therefore, space constraint: Min gaps between building changes for a students set  becomes valid for use.
Sorry for the inconvenience that I might have caused.

[Liviu Lalescu]

Sorry, I do not understand anything in this topic, but if it works it is OK 

[Benahmed Abdelkrim]

here is an example ilustrated by a screenshot

[Benahmed Abdelkrim]

here is an example ilustrated by a screenshot

In this example
Morning : 4 hours
Afternoon: 3 hours
The screenshot shows that students set did not change their room in in all afternoon periods.

[Liviu Lalescu]

I might understand something now 

[Benahmed Abdelkrim]

But their room changes every two hours in the morning. This change occurs during the morning break time.
While in the afternoon the room did not change.
Of course this is the desired result obtained by:
1 Making students and teachers available during the break time only in the afternoon periods (named B)
2. Use the space constraint: Min gaps between building changes for a students set .

[Benahmed Abdelkrim]

I might understand something now 

finally

[Liviu Lalescu]