HOW TO LIMIT THE NUMBER OF DAYS WITH A CERTAIN AMOUNT OF HOURS PER TEACHERS

[LucaFratini]

Hi, I need to find a way to limit the number of days one teacher can have six consecutive lessons, that is to say the full day schedule.

The goal is: each teacher (or that specific teacher) can not have more than one day per week with six consecutive hours. On other four days a teacher can have less than six hours, only one day per week can have a full day of six consecutive hours, not two or more.

If I say a teacher can have no less than three and no more than six hours per day, the system may put two or more days with six hours. I want to allow it to have one only.

I hope I explained my issue well enough...

Luca

[Liviu Lalescu]

Hello, Luca,

There is not a constraint for exactly what you need, but maybe alternatives:

1) Teachers max span 5 per day, allowing 1 day exception. This works only if you have 6 hours per day in the timetable.

2) Maybe you can use teachers interval max days per week.

3) Another useful constraint might be activities occupy max time slots from selection.

[Benahmed Abdelkrim]

... or maybe another alternative: changing to the mode morning-afternoon and use one day exception for all Teachers...

[niobee]

I have the same issue...
We have 6 hours per day, some teachers want to work maximum 4h a day, some others are willing to work up to 5h a day one teacher told me he can also work 6hours..

For the teachers willing to work 5 or 6 hours a day I would like this to happen only one day a week.
But then a second day could have a break, so the teacher is at school 5h, but only 4 of them are with students..

I allready put minimum hours per day (2 for each teacher) and maximum hours per day (4, 5 or 6 per day, depending on the teacher).. I also put maximum 1h a day and 3h a week for "ore buca" so hours when the teacher isn't in a class and 2h a day and 3h a week for those teachers who want to stay only 4h in class...

(hope I explained everything well)

Now my problem is that some teachers are working 5 hours two times a week.. I tried "Teachers max span" but it doesn't generate a timetable.. what else could I try to solve this issue?

[Liviu Lalescu]

Unfortunately, this is a problem in FET. I was actually thinking of making teacher(s) max hours daily only with 100% and allowing a one day exception of +1, but it is very risky, I need to be very careful and test a lot, because some timetables might become impossible if I make a logic mistake.

You could try max hours = 5 (or 6) 100% and max hours = 4 99% (ignore the FET warning there, about weights < 100%). This is not perfect.

Perfect, but it is quite some work: to ensure a teacher has in any pair of days <= 9 hours, add a constraint activities occupy max time slots from selection for each pair of days: all the activities of that teacher, select Monday and Tuesday with X (red), max occupied = 9. The same for all possible pairs of days for this teacher. The same for all the necessary teachers. For a teacher, there are 10 constraints to add, if there are 5 days per week.

I will add your words in the TODO.