I'm creating a schedule for the Faculty of Pedagogical Studies. I've encountered a problem that's confusing me.
Due to the large number of classes, we've defined elective subjects as separate groups. So we have Teacher Group 1, Group 2, and then Teacher Ethics, Teacher Academic Writing (as groups). For elective subjects, it can happen that there are two blocks, e.g., elective block 7 and elective block 8. These blocks must not overlap, because they are different elective blocks and each student chooses one subject from each block.
To prevent this, I added activity tags ig7 and ig8 and prohibited activities with those tags from occurring at the same time. However, when I try to move one such activity to a time slot that looks empty and has enough space, the schedule generation stops and reports that the subject cannot be placed there.
I'm sending the file I'm working on (the file is more than 512 KB, so I'm attaching a link), along with a desperate call for help.
My FET Timetable (https://pefunsacrs-my.sharepoint.com/:u:/g/personal/jelic_marijan_pef_uns_ac_rs/EbRo9wDeg-pGpRGnZxLQ9hsBdZ5H9uqEBZEpdnDiS7KSsg?e=ob43US)
It will help us if you tell us the id of the activity that you want to move and also tell use where you want to move it.
I done only a quick look, but it looks like most (all?) of your activities are locked in time. You probably only need to unlock the time.
I must sleep now and work tomorrow, so I will answer very late.
For example, activity 1169 to move to Wednesday in 16.00
I'm locking the activities in time because I do not want randomness during different version generation. Maybe I'm wrong.
Thanks for answering and help.
I guess it is about the tag (i) of activity 1169, because I removed it and it is possible. You have some constraints activity tags not overlapping.
We used the tag (i) to separate the appearance of mandatory subjects with groups and elective subjects in the same time slot (which must not overlap). We resolved this by introducing a restriction that (i) cannot appear together with (1st group or 2nd group).
So, is there another way to prevent the overlap of elective subjects and subjects that have groups? That could be a very useful option in FET.
I am sorry, but I don't understand. The constraint is good, but you want the impossible.
The constraint is set on activities with tags to "not overlap" groups and elective subjects. I guess under "do not overlap" means that they do not occur on the same day and time. Or maybe I was wrong.
Anyway, what do you suggest for me? How to restrict subjects with groups and elective subjects from appearing in the same time slot?
There are many ways to do this. One way is your way, with constraint activity tags not overlapping. Another way is to use automatic division of years by categories, or considering a subgroup = a real life student, and creating the necessary groups.
I was meaning your report: it is impossible to constrain "1169 to move to Wednesday in 16.00". I told you that probably in the same slot there is another activity with a conflicting activity tag.
But that slot Wednesday at 16.00 is not occupied by any other activity. It is blank. That was the thing that confused me.
For the first solution, "my" solution, it somehow does not allow me to put that subject in the empty time slot, which cofused me.
if you please look at the printed timetable.
I looked at it, and on Wed 1st hour there is an activity with 1gp and with 2gp. It is overall, not only for a students set. If you want only for a students set, you need to use activities not overlapping for each group of activities.
OK. I must think over on what you said. I will report what I did.
Quote from: Liviu Lalescu on November 05, 2025, 09:43:43 AMIf you want only for a students set, you need to use activities not overlapping for each group of activities.
Can you explain this to me? How to do it?
Either use activities not overlapping, with the exact activities, if this is possible, or create 3 activity tags for each students set, and make a constraint activity tags not overlapping for each 3 such tags.
I managed to solve this. Now, another problem that is odd, because time slots look available, but the activity won't fit. It is activity 278, 279 which should be on Thursday at 10,
https://pefunsacrs-my.sharepoint.com/:u:/g/personal/jelic_marijan_pef_uns_ac_rs/EbRo9wDeg-pGpRGnZxLQ9hsBdZ5H9uqEBZEpdnDiS7KSsg?e=TSmZNl
I'm sorry, but I don't understand. 278 has same teacher and students as 279, so they cannot overlap. Also, 278 has a locked time as:
Time constraint
Activity with id=278 (2 - др Марија Цвијетић - Дидактички материјал и асистивне технологије у инклузивном одељењу (и) - (П),иг8 - Учитељи - 4. година Дидактички материјали и асистивне технологије у инклузивном одељењу)
has a preferred starting time:
Day=Четвртак
Hour=08.00
Weight (percentage)=100%
This activity is not permanently locked, which means you can unlock it from the 'Timetable' menu
No, they should not overlap, but follow one another. Although, as you can see if you deactivate constraints for these activities, the whole Thursday morning is free, but the sucbect cannot be placed in the time slot after the "П" which is Predavanja (Lectures) (as oposed to "В" Vežbe (Seminar). Although none of the constraints is interferring, the timetable can't generate. I guest that the problem might be in the Classrooms, although I left a lot of classrooms to be chosen from.
Sorry, I don't understand, because your file above was solvable on my computer.
It is because I turned off the time constraint for the 279. Try turning it on. (I'm working on the file all the time.)
I turned on preferred starting time for 279. It stopped at ID 1161 I think; I made home rooms for 1161's teacher 100% -> 99%, it solved with difficulty, but it solved, and we got this constraint home rooms broken. I understand with very much difficulty the Cyrillic characters, sorry, but I think these home rooms are all occupied.
Thanks. I will try to loose for a little bit the homeroom constraints.