a teacher in first 2 hours in a single week day

[y]

Hmm, this is no good.

1) I think you made other mistakes and FET is good in this aspect.

2) If you didn't make other mistakes, FET has a problem here.

3) It was just bad luck.

So, please:

a) Send me your file (by email).

or

b) Try on your new file to make the constraint from 3 to 7 (wrong). It should solve as fast as now.

I tried (b) and you're right! With a time-out of 15min I got 8 out of 10 timetables! Strange... I don't know which one of 1,2,3 you mention happened. I can still send you the file if you still want to have a look at it.
Thanks again!
Looking forward for the new version

[Liviu Lalescu]

I'm glad it is this way. I think (1) or (3).

I am quite busy with last minute updates to FET, but I might use your file in the future.

[Chafik Graiguer]

I want to have a teacher working one day (no matter which one) only the first 2 hours, and all the other 4 days according to the general constraints. How can I do that? I tried with "... hourly interval max days per week" but this is not the right constraint.

Any ideas please?

There is a solution using dummy activities
Say you have 6 time slots per day
For that teacher, add a new activity without students:
- Split 1, Length: 4
-An activity has a set of preferred time slot: Disallow all first and second time slot (all days)

You have to adapt the trick depending on working days per week for that teacher

[y]

There is a solution using dummy activities
Say you have 6 time slots per day
For that teacher, add a new activity without students:
- Split 1, Length: 4
-An activity has a set of preferred time slot: Disallow all first and second time slot (all days)

You have to adapt the trick depending on working days per week for that teacher

Thanks for the tip. I'm not familiar with split activities, I'll check it. I'm still a newbie at FET (usage of less than 2 months). But the problem is solved using the interval constraint as Liviu suggested, for both teachers.

Thanks anyway!