Break Time and no gaps Time for teachers

[technoweb]

Hi everybody,

In my FET i have 3 hours in morning, 2 in afternoon and break lunch.
I want to place two activities with same teacher and 2 duration times in the same day (act.1 in morning and act.2 in afternoon). But i have constraint max of teacher gaps per day = 0.

How can i do it ?

To simplify my FET i made a sample separatly.

[Volker Dirr]

Your dataset is impossible, because students are not allowed at "10:00" and "break", while teachers are not allowed at "break" only.
So the teachers will get a gap at "10:00", but you disallowed teachers gap. So your dataset is impossible.

There are at least 3 variants how to solve it:
1) increase teachers max gaps up to 1.

or

2) remove the students not available at "10:00"

or

3) give the teachers also other activities, so they can teach other students at "10:00"

[technoweb]

Ok thank you.

Is there not a way to specify that the gap before the break is not counted. Or otherwise the gap concerns half a day ?

[Volker Dirr]

If you use the custom FET versions (Moroccan or Algerian) the gap is not counted and you care about half days only.

Liviu: i think i should ask once again: "Moroccan" and "Algerian" names are "bad" names, because that names suggest "incorrect" infromation. It will be better to set names like "Half day Version", ... or somethink like that.

[technoweb]

Ok Thank you Volker.

[Liviu Lalescu]

If you use the custom FET versions (Moroccan or Algerian) the gap is not counted and you care about half days only.

Liviu: i think i should ask once again: "Moroccan" and "Algerian" names are "bad" names, because that names suggest "incorrect" infromation. It will be better to set names like "Half day Version", ... or somethink like that.

The Algeria and Morocco are designed specially for those countries. But he can use even the official FET, with the tricks described in the official FET fet-v.v.v/examples/Morocco directory.

[Volker Dirr]

I think that is not "true". it was just "luck" that the guys from that countries asked first to care about morning and evening.
for example in Germany are a lot of different school systems: "Grundschule", "Hauptschule", "Realschule", ...
They should all use the official FET version, since that fit best for them.

But there are also a few special schools here in Germany called "Abendrealschule". They shouldn't talk the official FET version (if they don't want to work with those workarounds.) The Morocco or Algerian Version will be much better for them.. So it was just look; if a guy from a "Abendrealschule" had ask your first, then the name won't be "Moroccan" - it would be "Abendrealschule"?! In fact there is no special stuff for that "country". The special stuff is the way how it cares about evening and morning. I guess it will be very similar in nearly all other countries. That is why the customs names are currently chosen "bad". They should be renamed with better names; of course we can still add recommended  countries for that versions. But in fact i bet that (recommended countries) won't be always true. I am sure there will be (a very low number of) "school" systems in that 2 countires that also could better use the official FET (for example a evening school / night school for work workers only, a driving school, ...)

[Liviu Lalescu]

It is too difficult.

There are constraints specially made for Algeria and Morocco.

[Volker Dirr]

I think you didn't understood. "Abendrealschule" and other schools need exactly that constraints. So it is just confusing that you name them "Algeria" and "Morocco", since "Abendrealschule" and other need the same. I am not talking about merging that 2 versions. Just the name are confusing, since many other schools can use the same versions, even they are not located in Marocco or Algeria.

[Liviu Lalescu]

Morocco has teachers' one and two days exceptions, and other teachers' constraints.

Algeria has also some custom Algerian teachers' constraints.

FET official can solve Morocco and Algeria not perfectly, using tricks described in fet-v.v.v/examples/Morocco. So, Abendrealschule could solve their problems even with FET-official.

[Volker Dirr]

Of course they can try official with workarounds, but using the Algeria or Morocco version of fet will be much better (depending on the exact needs of "Abendrealschule"). That is why that names are "bad". You didn't do modifications for the country, you done modifications for teacher constraints. That is why the name of the versions shouldn't be a country name, it should be a name that point out the modifications in the constraints, so other users will easier understand if that versions fit better or not.

[Benahmed Abdelkrim]

I think mr. Volker is right, because this half day specification is not special only for these two countries. There are other countries all over the world that share this specificity. So in my opinion I agree to change the name of these 2 versions. A name that gives correct information (like: two-time version, half day version, Discontinuous time Version...) , so that other people can use these two versions without any hesitation.

[Volker Dirr]

Thinking some more about this: The disadvantage is caring multiple FET variants. Maybe we should rethink about doing their request fine with the official version.

I think one (maybe) needed is following constraint:
constraint teacher is working only in one out of two set of times.

So if teachers should work only in the morning or in the evening, you need to add as many constraint as you have got days:
the first constraint:
    1. set of times contains all morning hours on Monday.
    2. set of times contains all evening hours of Monday.

the second constraint:
similar with Tuesday.
...


This constraint can be also used to avoid the problem of an other user. I remember a guy with 3 shifts (morning, evening, night). His request was, that a teacher is not allowed to teach the night shift and then the next morning shift.
That could be also solved with the constraint above: "constraint teacher is working only in one out of two set of times."
So this time he need to setup like this:
the first constraint:
    1. set of times contains all night hours on Monday.
    2. set of times contains all morning hours of Tuesday.

the second constraint:
...

So again as many constraint as you have days (or days-1 if you don't work over weekend).

[Volker Dirr]

The other will be the gaps constraints.
So a constraint like:
"max gaps per day in an interval" and "max gaps per week in an interval" might be maybe enough.

So you maybe need to add only 2 constraints:
1. "max gaps per day in an interval" with the interval : "first hour of of morning" up to "last hour of morning"
2. "max gaps per day in an interval" with the interval : "first hour of of evening" up to "last hour of evening"

[Benahmed Abdelkrim]

I believe it's time to rethink the 2 variants of FET with the official version.
This work is feasible by the addition of new time constraints for teachers and students. I myself realized this fact through adding pseudo activities to teachers and student groups. These are considered gaps. I got acceptable timetables with all student groups. But for teachers there was one or two that I have to manually edit.

It is while working on the official version that I recently discovered this bug that accelerated the release of version 5.31.5.

There was a lot of work to be done, especially for teachers because they did not have the same number of hours per week, and I had to think of teachers one by one.

The time was lengthened in this way (of the hours of waiting), which I have now abandoned this project.

Now the idea has been raised again but in another way that has encouraged me to intervene here.

I believe it is possible to use the official version to realize time tables in the Algerian or Moroccan way.
For this purpose it must consider the addition of the following time constraints:

1. Min hours in a time interval
Interval = first hour of morning(or afternoon) - last hour of morning(or afternoon)
2. max gaps in the last(or first) hour of morning(or afternoon) for students (set)
3. activity(ies) ends students interval.