A teacher does *not* want to start in 3rd or 4th period

[pg788]

I understand this might be restrictive, but a teacher doesn't want to begin in 3rd or 4th, since there is traffic. Can I use max time slots occupied from selection to impose this?

[Volker Dirr]

hmm...
How many hours per week has the teacher?
How many days per week and how many hours per day has the timetable?
Maybe it will be easier to increase the min hours per day?
Maybe there is an other nice varitant if we know that.

i hope your timetable isn't too difficult right now without it, since in fact it might result in a higher number of gaps.
So i am not sure if it is not as bad as without such a constraint.
I just think he will maybe get hour 3, 4 and 6. Because of too much traffic it mean he will already drive like if he need to start at hour 2.
now let's assume he will get hour 2, 4 and 6. That is in fact not better, since now he must leave home the same time, but this time he doesn't sit in the car, this time he is waiting in the teacher room. Of course he can also leave home in the first variant as in the second one. In that case he also don't need to "wait" in the car; he can also wait in the teacher room (just in hour 2 instead of hour 3)
So it will be a psychological problem only if you can't keep the number of gaps as low as before.

[Liviu Lalescu]

I understand this might be restrictive, but a teacher doesn't want to begin in 3rd or 4th, since there is traffic. Can I use max time slots occupied from selection to impose this?

So the teacher may only begin on 1st, 2nd, 5th, 6th, etc? Unfortunately, I see no solution using the official FET for this. Also, adding a new constraint seems complicated and I am not sure it is possible.

I will add your suggestion in the TODO.

[pg788]

The timetable is solving within 5 seconds, so it is not too tricky currently it seems.

The teacher has 14 hours in a week, needs to have classes on five days, with a minimum of 2 hours in a day and maximum 5 hours in a day. I have kept the number of gaps for her as 1 per week (although she desires no gaps).

@Liviu: yes, she is fine with starting in 1st, 2nd, 5th or 6th.

[Volker Dirr]

so you have got 7 or more hours per day in the timetable?

[pg788]

Yes, we have 8 hours in a day, but we avoid using the 8th since students are exhausted by then.

[Volker Dirr]

ok. so in normal case only 6, but up to 8 if it is not possible an other way. Similar at my school.
I suggest to give her max 4 days only. THAT will save time! It will nearly also automatically avoid to start in the 3th or 4th if she teach only up to the 6th hour. All teachers at my school with less than 18 hours per week have got at least a free day. even if they are class teachers. Of course that teacher also wanted to see "their" classes always. But a free day is better and nobody complains about the free days in the last years yet. Not the teachers, parents nor the students. Maybe it is different if you have students in class 1 or 2. At my school we start with class 5 and there it is fine.

An other variant might be to force 5 of her class activities to start in hour 1 or 2. if your dataset is still so easy it might be also very easy. But don't forgt the big disadvantage: If that teacher get such a special constraint all other teachers might be angry if you don't care about them the same way.

[pg788]

All teachers are required to come on five days and have minimum two classes each day according to my college rules. Moreover, at least one 7th period in a week is compulsory for every teacher.

We are implicitly required to accommodate requests of senior teachers (some are due to retire within the next year). We try our best to accommodate most requests of teachers wherever possible (especially relating to starting early or late and fewer gaps).

[Volker Dirr]

ah. ok.
I must admit that i don't understand why a college do those rules. (forcing 5 days and 7th hour, even if part time teacher only) If teachers have got small children i always (try to) avoid to give them hours in the afternoon and/or to give them the 1st hour (since they need that time to bring their children to another school or kindergarten)

In my country the teacher with only half of the number of hours compared to a full time working teacher (28 hours per week) have got even the right on a free day by law.
I hope your college pay those teachers well if they need to travel as many times to school as a full time teacher. Mathematically a teacher with half of the number of hours should come also half of the day, since the get only half of the money. i know most schools can't do that; but forcing them to come all days?

I think you should force 5 "class" activities into the 1st or 2nd hour to care about your college rule and to care about that teacher.

[pg788]

Oh, I should have clarified, the teachers with 14 or 16/17 hours are all full-time teachers. No problem with pay   

Part-time teachers have less than 7 hours a week. The rules of the compulsory 7th period and daily classes are only for full-time teachers.

We don't get personal office space, so no teacher prefers gaps as there is no real place to prepare for classes other than the library which is usually crowded with students. These are the problems of publicly funded education in third world countries

[Volker Dirr]

full time with 17 hours only. Nice. I want to have that also :-)

we (most German schools) also don't have office space for teachers. At my school i have got only a crowed teacher room; not enough space for all teachers even if we stand only. so we just move into a free class room if the teacher room is too full; since there is always a room free somewhere if the students are in the gym, since lab, ...
Or i prepare experiments in the physics library (so not the room with the books; the room with all the physics apparatus - i sadly don't know the English term for that)

But returning to your problem:
i suggest to choose 5 activities (in best case 5 activities with min n day with 100% constraint) and just set a activities preferred time constraint and allow only 1st and 2nd hour at 4 days and set the 5th activity in the 7th hour at another day.

[pg788]

Thank you for the suggestion, I will try that.

16 or 17 hours is for junior teachers. Senior teachers have 14 But then this is university level, not school.