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FET Support (English) => Get Help => Topic started by: marco.buzzanca on September 06, 2025, 02:51:56 PM

Title: How to debug impossible timetables
Post by: marco.buzzanca on September 06, 2025, 02:51:56 PM
Hi, and thanks for your Wonderfull software.
I'm working to close the timetable of my school but FET is unable to place 3 activities (Vincolo d'orario di base obbligatorio infranto: non piazzata l'attività con ID= 502)
I have tried several changes but I can't understand which is the problem. How I can debug the timetables?

Ciao, e grazie per il tuo meraviglioso software.
Sto lavorando per chiudere l'orario della mia scuola ma FET non è in grado di inserire 3 attività (Vincolo d'orario di base obbligatorio infranto: non piazzata l'attività con ID= 502)
Ho provato diversi cambiamenti ma non riesco a capire quale sia il problema. Come posso eseguire il debug dell'orario?
Title: Re: How to debug impossible timetables
Post by: Liviu Lalescu on September 06, 2025, 02:54:19 PM
Hello,

You are welcome! Thank you for your kind words!

You can send me your fet file, and I'll have a look. You can attach here or send to my email, fet4 AT lalescu.ro.
Title: Re: How to debug impossible timetables
Post by: Volker Dirr on September 06, 2025, 02:59:21 PM
There are mainly 3 variants how to do it:
1) Always do small changes only and run the timetable. If it doesn't solve anymore, then it must be because of (a combination with) the last constraint/activity that you added/modified.
2) View the last impossible activity that can't be placed. Then view the timetable and check the room, teacher and students timetable. Try to place yourself the last missing activity. In many cases you can see why it is impossible to place it.
3) Do an minimum example that still contains the bug. So try to remove many constraints, but keep it impossible! Then maybe also try to delete students and or teachers and try to keep it impossible. Do that as much as possible. Then the file is much smaller and then it is much easier to understand why it is impossible.
Title: Re: How to debug impossible timetables
Post by: marco.buzzanca on September 06, 2025, 03:03:13 PM
xxx
Title: Re: How to debug impossible timetables
Post by: marco.buzzanca on September 06, 2025, 03:06:57 PM
This is the file I'm working on now. It is a debug version.
Thanks for your support
Title: Re: How to debug impossible timetables
Post by: Liviu Lalescu on September 06, 2025, 03:14:47 PM
I'll see now your file.
Title: Re: How to debug impossible timetables
Post by: marco.buzzanca on September 06, 2025, 03:24:19 PM
Removed, thx
Title: Re: How to debug impossible timetables
Post by: Liviu Lalescu on September 06, 2025, 03:47:47 PM
I added max span 5 allowing 1 day exception for each teacher, then deactivated for 1-Eva, 2-Tor, 6-Gra, 6-Ran, and 7-Cri. It solved. I attach my file and a solution. You need to rethink about these teachers.
Title: Re: How to debug impossible timetables
Post by: marco.buzzanca on September 06, 2025, 03:58:12 PM
Thanks a lot!!