constraints priorities: all vs 1 teacher

[mercurialuser]

Scenario 1:
Max gaps for ALL teachers per week: 2
Max gaps for teacher TEST per week: 3

Scenario 2:
Max gaps for ALL teachers per week: 2
Max gaps for teacher TEST per week: 1

What will be the max gaps per week limit value used by FET for teacher TEST in scenario 1 and 2?

Francesco

[Liviu Lalescu]

All the constraints are satisfied.

Scenario 1: Max gaps teacher TEST: 2

Scenario 2: Max gaps teacher TEST: 1

This is not very user friendly, but it is difficult to change now. I think it is in the TODO.

[mercurialuser]

I did not find it in the TODO, not under my name, but I remember that last year we talked about "unrolling" the ALL constraint to one constraint for each teacher, in order to avoid repetitive manual tasks... this in the GUI...
infact, to avoid this problem, this year I wrote a little script that creates parts of the xml file and injects them in a template, so that I can more easily control the constraints.

Francesco

[Liviu Lalescu]

See items #82 and #84. I also added your name now.

[mercurialuser]

I was writing this... I found references to this problem in the Italian forum... it seems a problem we face in Italy... :-)

Thank you
Francesco

[Volker Dirr]

i have this "problem" too (increasing the number of gaps for a few teachers). I solved this pretty easy: i just gave them a pseudo activity (only the teacher, but no students or room).

[mercurialuser]

You say to create a pseudo activity, so FET can put the activity in the gaps if FET needs to... if FET put the pseudo activity as first or last period of lesson you can just discard it...

[Liviu Lalescu]

i have this "problem" too (increasing the number of gaps for a few teachers). I solved this pretty easy: i just gave them a pseudo activity (only the teacher, but no students or room).

You say to create a pseudo activity, so FET can put the activity in the gaps if FET needs to... if FET put the pseudo activity as first or last period of lesson you can just discard it...

There might be problems if you need to care about max/min hours daily for teachers.

[Volker Dirr]

Liviu is correct. A pseudo activity of course effect the min and max hours per day.
So depending on your dataset that might be a problem.
I added those "pseudo" activities only for the staff members. They are always at school, but teach only a very low number of hours. So that guys can get more gaps than all other teachers. That guys won't get problems with max hours per day, because they teach such a low number of hours (per week). That guys will also not get a problem with min hours per day, since they are always at school in the office, even if there is no activity placed at the whole day.
I guess most guys will use this trick/request also only for a few teachers from the staff team or trainee teachers. Also for trainee teachers it won't be a problem at most schools/dataset.
This "trick" is not used for a "normal" teacher. I care about "normal" teacher by using the "all" constraints.