Can't find a solution!

[Araleworld]

Hi There! Is almost 1 monthts that I am "playing" with FET to get a result on my timetable...

But for the moment no way....

Last year I did it... but this year we had some changes that dont know if it's the reason why I am not getting any result....

I think that this is the last version of file that I am working with...

Could anyone take a look?

My first big doubt is about groups/subgrups etc If I am doing in the way that fet expected or not....

The big point is that my timetable is quite complexe... Almost 80 teachers and more that 1000 activies...

the file is too big for attach... then here is the drive link:

https://drive.google.com/file/d/1_Bb-yTNXhqiLepXMCe_OT27T4xQhMRyf/view?usp=sharing

Really thanks.

[Liviu Lalescu]

Hello,

First of all, I think if you archive your file it will fit here (under 512 KB). It might be better to attach it also on the forum here.

I don't know exactly your problem. The students sets seem fine. Maybe you have too strong constraints, especially not available students/teachers. I advice a progressive approach, from a working file (with almost all constraints deactivated) add constraints in the order of importance.

[Araleworld]

Now I am out of home will archive it and post it once arrived.

My problem right now is that it get stuck in activity 915 aprox...

I had wait even 1 hour...

Last year maximum time of get and timetable was 20 min and most of the times was much more less...

I think that I had check everything related with the activity that got stucked but even so didn't find the reason why.

[Araleworld]

Here ir the zip file.

[Araleworld]

Well most of the constraints were in order to help the program to find a solution...

Had remove most of them and even worst

Half activities placed (600) in 2 seconds... but nothing more...and when the program arrived to 303 trying to place activied nothing else happened

The last activity where was not able to continue is exactly the same as the fet with all the constraints....

The new file attached...

[Liviu Lalescu]

I see you only deactivated a few constraints. You might want to deactivate more and then put them back.

If the program goes fast to 600 then back, there is no need to wait so much to 303.

[Araleworld]

Thanks Liviu for your reply!

A question about the algorithm...

If with these constraints there is no solution means it's impossible?

Or if I remove all of them and then got solution and start to put them slowly, is possible to fine one?

Is like the algorithm has memory and I'm every execution has info from the previous one?

Really thanks for your time!

[Liviu Lalescu]

You are welcome! 

I hope FET will generally fail only if there is no solution.

Remove all the time and space constraints and see if there is a solution. Then add them one (or a small number) at a time, and generate to make sure. If there is no solution without any constraint, then you probably have a mistake.

The algorithm does not have "memory".

[Araleworld]

Thanks to your "magic"  words I had find the problem.... then I have a solution!!

I have now a timetable!!

Thanks a lot again!

[Liviu Lalescu]

I am glad it worked!