Difficult timetable this year

[sinisav]

Im 5 year user of FET timetable and so far I have been able to solve problem of difficult timetable in my school. However this year is very difficult. I have managed to came to 528/525 activity. Using same generator key and change parameter but only could get worse results. Could you please help me with suggestions with this fet file.
EDIT: Didnt find option to attach file so here is a link to pcloud: https://e.pcloud.link/publink/show?code=XZ5UmWZ3jKY3UapqCzAjyDEmvJHY7Q6boi7

[Liviu Lalescu]

Hello!

I will have a look at your file. You could have attached it here on the forum, it is a "Click or drag files here to attach them" button underneath the text. If it is too big, you can archive it.

As a first note, you use an ancient version of FET. I would advise you to update to the latest version. Also, same generator key is not recommended if the file does not solve. Also, I think you mean 552 total activities?

What constraints may I relax, if any?

[sinisav]

Yes I misspelled number of activities it is 552. I could only relax some teacher are not available time but not for all because we have teacher working in another school and another city. Try to delete actvity must not overlap all off them.
Pcloud link: https://e.pcloud.link/publink/show?code=XZwTbWZ3yOXB7DPHxBSM1QKv2sODyB8zgI7
File is too big for attach.

[Liviu Lalescu]

I hope I have some maybe good news:

I firstly deactivated all the space constraints, and noted that the generation locked at 514/552 (I generate multiple on 8 threads with FET-6.9.5, so it is generating 8 timetables in parallel). So I saw its id = 96 and it was related to students 1 DT. Seeing the partial timetable of the highest stage showed that there is a gap in the timetable of the students 1 DT G2. So I added a dummy activity with duration 1 to students 1 DT G2 and to my satisfaction I obtained a timetable (with very much difficulty). Note that all the space constraints were deactivated, so it might be useless. I attach, archived, the file and the solution (k12).

I am now generating on more threads with all the space constraints activated back again and that dummy activity added, but unfortunately it seems very difficult. I'll announce you if I get something, but maybe you could lower the space constraints. Or work on something from my solution to k12 above.

As a personal request, please consider and spread the word that this software is completely free/libre, and depends on kind donations/sponsorhips from the users.

[sinisav]

Unfortunatly space constrain are must have because that is room wit computers. I will try your solution but I think that this may not be problem because 1DTG2 I put in second shift. Still trying to get results. Thanks for your help. Waiting to see could you solve this. You may from second file delete Activity must not overlap and try.

[Liviu Lalescu]

I think you must shift activity id 444 one hour earlier, because otherwise is a gap for students 1 DT G2. The dummy activity I added in my k12 above did this as a trick. I think this is the error in time allocation.

About space constraints: aren't any which can be relaxed? I am trying now all space constraints 95%, but proves too difficult.

[sinisav]

You are correct. I forgot to shift ID444 one hour earlier. Now Im trying to see what will hapen with generator key whit i have got 528/552. And Im trying to relax space INFORMATIKA for activity duration 2 hour. This is all I can done.

[Liviu Lalescu]

I obtained something. Unfortunately, there are some broken space constraints. I did all the space constraints 80% and there are 15 broken such space constraints. Please see my attached file and solution.

I will try now as you said, room INF is not so important, but the other 100%. But I don't think it is possible.

[Liviu Lalescu]

I obtained another solution to the same data (80% all space constraints), I attach it here. It took 1 hour.

[sinisav]

UPS misunderstanding. You didn get me right. Room INF is very important because students teach computer science. I have change one subject Informatika 1IT from room INF to K5 and KRiI and didnt get good results. However I have maximaly relaxed constrains activity are not overlaping and teacher not available time and get 545/552 activity placed. Could you now look in this file, and please dont change space constrains, because it very important.
Pcloud link: https://e.pcloud.link/publink/show?code=XZ5UmWZ3jKY3UapqCzAjyDEmvJHY7Q6boi7

[Liviu Lalescu]

I hope I have good news: I obtained a solution. See the attached files below.

If the work is good, please don't forget what I wrote above about financial help for this project.

[sinisav]

I will inspect timetable. So far I saw one error. Willing to contribute in next few days. I have also contributed with translation of TiTiTo to serbo-croatian language.

[Liviu Lalescu]

Unfortunately, it seems that I cannot obtain more timetables. Your file is very difficult. I might try some more, not sure.

Thank you for your kindness! Did you update your FET to the latest version?

[Liviu Lalescu]

I obtained with great difficulty another timetable. Attached the solution file.

[Liviu Lalescu]

And another one, attached. This one finished in only 8 minutes.