Time Constraint - How to set a teacher to begin early

[matthews]

Hi!

I tried searching for help unfortunately I didn't find an answer.

How can we force FET to make a teacher always start from 8 AM? Students have a cool constraint called "A student set begins early", what I'm basically looking for is "A teacher begins early".

Can this be done somehow, did I miss something or is it only possible if I use "Teacher not available times" to limit and force FET to schedule the teacher to always start at 8 AM?

Thanks for the help! Great program!

[Liviu Lalescu]

You can use the magic constraint activities occupy max time slots from selection. Please read the help of this constraint for details.

More details from me: If you want for a teacher that each slot 8 AM of each day to be occupied (5 days per week), add a constraint activities occupy max time slots from selection, activities = all activities of this teacher, selected slots (with X or red) = slots other than 8 AM of each day, max occupied = duration of activities of this teacher - 5. I might be mistaking, so please do some small tests and also consider yourself the logic of this (read what this constraint does in its help dialog).

[Volker Dirr]

I highly suggest to think twice before adding such a constraint. normally that constraint is not needed and/or impossible.
At most schools there are much more teacher like to start the 1st hour than there are groups. So it is impossible to do that.

Some teachers say: "I must teach 1st hour already, because i need to fetch my child from kindergarten in the last hour".
But in fact in this sentences is a big bug. If the teacher need to fetch the child from kindergarten it doesn't mean the teacher must start 1st hour. It only mean teacher is not available last hour. So the correct constraint is using teacher not available constraint in the last hour.

There are a lot of other "similar" reasons. (But my bus arrive at, ... . Always if you think a bit more about that, you will see that even such a reason is wrong. Even if the bus arrive early it won't help the teacher if he teach 1st hour. Imagine he teach the 1st hour, 2nd hour a gap and 3th hour teaching again. If the teacher get 1sh hour "gap" and 2nd and 3th hour teaching it is as worse as starting the first hour. He won't come home earlier home by that constraint and he also don't have an other number of gaps and he also don't have an other number of hours that day. So such a constraint won't help that teacher. You only make the timetable more difficult without helping someone.

Also before adding such a constraint think twice! Ask why that is needed. Think twice if it gives an advantage. It won't help if a later gap "destroys" your advantage again!

The only maybe critical teacher is the teacher that care about the substitution table. In large school it is easy: that teacher normally get "office" hours at the first hour. So just place him that pseudo/office activities and use preferred time for that hours. At small and medium schools it is a bit difficult if that teacher get less than 5 office hours for his work. Medium schools can use Livius trick above. Small schools can normal schedule a timetable also with pen and paper only.

[Vangelis Karafillidis]

Generally speaking, timetabling has some issues. I think that the most crucial factor of making timetabling difficult is the teachers' attitude itself. No timetabling application can solve this problem. Teachers demand and demand and demand. You need to judge by yourself if there is really a reason to add even a single constraint in FET. Bear in mind that entering more and more constraints in a timetabling problem, might result in an unsolvable timetable... Timetabling applications are vastly different from applications such as Microsoft Word or Adobe Photoshop. Entering a constraint is easy regarding the GUI manipulations of your application. Unfortunately, it seems to be as easy as selecting a font in Word or a brush tool in Photoshop. But, adding unnecessary constraints to FET -most of the time- causes trouble. So, please consider carefully which constraints are really needed and enter just these ones.

[Volker Dirr]

Exactly. Luckily not all teachers are like that. Just a few, but this few guys will be responsible for a worse timetable of the other teachers if you don't watch out. The "sweetest" teacher i remember explained me all his not available times and free days and didn't notice that it is impossible to place his X hours into the left X-1 free time slots.

[matthews]

Thanks guys! And you guys hit the nail on the head. I wanted to figure out how to do this as a courtesy to the teachers at my school asking for this because they commute and bring their children with them to school/kindergarten. Most teachers are reasonable though, the only problematic ones are those with small children and if they also work at different schools.

I managed to do it with your help so that it worked in the end. FET is a fun program, I actually enjoy the logic exercise it provides but I agree that the less constraints the better.

making timetabling difficult is the teachers' attitude itself

Definitely, there are like 3-4 people at my school who throw a tantrum if their timetable isn't neigh perfect, coincidentally these people were in charge of making the timetable before we moved onto FET. They somehow miraculously always had perfect timetables and when others complained they just shrugged it off, last year one of them had a gap and two others had to stay until 3PM. The headmaster should tell them to suck it up but he wants to stay on everyone's good side.