Author Topic: can't find the wrong constraints  (Read 675 times)

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flauta

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can't find the wrong constraints
« on: September 19, 2015, 02:05:57 AM »
I have generated many times the table, every time the last activities that don't close are the same.
But even if I disable all the constraints for that activities, the result is the same.
Please can someone help and find which are the wrong constraints?
Andrea

Volker Dirr

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Re: can't find the wrong constraints
« Reply #1 on: September 19, 2015, 03:46:09 AM »
Sadly i can't see an obviously bug in your dataset. Difficult to say without reading your whole activity planning, and you use several mutal strong teacher time constraints which make it difficult to think/read about that problem. In worst case you "only" need to wait a few years to get a solution.
I fear you need to lower some constraints. Difficult to say which one you should lower first, because i don't know the reasons for the constraints. Maybe start with constraint that have less then 100%. Then increase constraints like "max intervalls", ...
I can only recommend to lower them as long as FET didn't solve it. As soon as FET is able to find a solution you can try to add constraints again step by step to get the best timetable.
I also recommend to use only 100% (or 0% weight) if you hunt for such bugs, because it's much easier to find obviously bug then. You can modify them to other weights later again as soon as you want to generate the final table.

flauta

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Re: can't find the wrong constraints
« Reply #2 on: September 19, 2015, 04:00:38 AM »
Sadly i can't see an obviously bug in your dataset

First good news! I was thinking I couldn't see an error...

The generation is slow but not <so> slow ;-) now in 4-5 hours I get a timetable with only 2 or 3 activities not placed and I can finish it by hand.

many thanks for the suggestions!
Andrea

Liviu Lalescu

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Re: can't find the wrong constraints
« Reply #3 on: September 19, 2015, 04:31:45 AM »
I tried this:

1) Deactivate all min days constraints and the 3 constraints teacher max hours daily with weight <100%. It solved in less than 30 minutes.

2) Lower the weights of min days constraints from 99% to 80% and from 95% to 50%. Also lower the 3 max hours daily constraints for teachers to 50%. It is at 207/209 placed at 20 minutes.

The conclusion is for you to draw.

I attach the file for 2).