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Hey All,

I have the following FET file, the file solves just fine as is and in a reasonable time, under 10 min for most runs.

How ever when I set

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Time constraint
All teachers must respect the maximum number of hours continuously
Weight (percentage)=90% (was 80% before)
Maximum hours continuously=2

the timetable no longer solves even after running it for a long time (5 hours was the longest try)

Is this to be expected, do I get it to some dependency issue with other constraints ?
The goal is to reduce the number of teachers with 3 lessons in a row to the minimum

Thanks,

Daniel

I have the head master and some of the other stuff reviewing the timetable, once they confirm it I will upload the file

I think it will be a good addition, and ye just from the way the data is structured I think it is a big change to the system.

The activities grouped solution worked perfectly, the timetable took it time(1 hour 12 min) but did fully solved and gave a very good solution. On per and even to my view superior to manually solving it, though some of my collages disagree.

Unfortunately my C skills are a bit rusty , I don't even have a compiler setup.

For now I will explicitly group the activities I need to span across breaks and once I have more time think about a more elegant solution.

Thanks,

Ye it would be very nice to just have a check box saying allow doubles to span across breaks , maybe you can add this option in a later version.
I m working on making a way to group 2 activities arbitrarily, if you check now you can right click lessons in the academic blocks screen, and set up a link but this is limited to splits of the same lesson, not a very good solution and not very clear to a user.

Once I figure something better, I will let you know.

If you like I could send you a link to our exporter to have a look

I think that would be a useful option to have, but may not be so easy to add with the way the breaks are setup.
I will try to automate it on my export side, giving the option to setup a double as duration 2, or the activities grouped constraint.

Thanks,

Daniel

Hey,

After some testing with FET on our time tables, I have found that one of the main issues we have is related to double lessons, breaks and the teacher max hours continuously constraint. Our teacher are allow to work max 3 hours continuously.

To get a workable time table I had to allow double lessons to span across breaks, to do that I just removed the break from FET. this allows double lessons to be placed at any time slot. however this results in the teacher max hours continuously constraint not knowing about the break and not allowing a teacher to have say 3 hours break and 3 hours again, this would seem to FET like 6 hours in a row but is actually perfectly valid.

The only way I found so far to allow this to work this way is use the 2 activities are grouped constraint to group 2 activities, but this results in a lot of manual work.

Is there any other option ?

Thanks
Daniel

Hey All,

In our high school timetable we have 2 types of lessons length in a day, 40 min lessons and 1 hour lessons. To address that we setup our lessons as 20 min lessons and made:
Single lesson = duration 2
1 hour lesson = duration 3
Double lesson = duration 4

Our day looks like this:
20 min x 6
break
20 min x 7
break
20 min x 3
day ends

We don't allow 1 hour lessons or double lessons to span across a break and FET takes care of that just fine as is.
ATM i m testing each form on it's own with minimal constrains, to make sure our lessons structure is valid, Over all FET is able to generate the form time table but it is slow we have ~250 activities in a form and with no constraints (just basic comp) it can take up to 10 min to get the time table for a single form.

With our primary school that got about 600 activities in all forms with no constraints but the basics the timetable is ready in a few seconds.


I think there are 2 mine reasons for this:
1. If FET slots a 1 hour lesson in the first part of the day it must be followed by a 1 hour lesson or else there will be a free 20 min slot and we don't have 20 min lessons or free space and it makes the solver work harder for no good reason. I could not fined and constraint to use for this case.

2. Options blocks where students are split to groups can have a structure of 4,3,2 lessons, and FET can slot options with duration 3 and 4 at same time resulting again in unnecessary searching. for this I was thinking I could add a activities have same starting time constraint . for activities with the same duration for a block, will this result in a speed up in your opinion ? I can give it a try but it is a lot of work to add all the constraints

I attached a file with a single form.

thanks,

Daniel

The file I have uploaded dose solve after about 1h 30 min, how ever the lesson spread is not optimal, so working on some more constraints to try get it optimal and once done I'll upload the new file.

I have quick question, do you think the order of the activities effects the way it is being solved ?

So if say I export like forms 5, 4, 3... first, atm the order is form 1,2,3... and so activities from this forms are placed better (in the morning) the the later forms 4, 5 who get more lessons in the afternoon

The file is not working atm, not solving but I should get it to work today, or else

I will upload the final version soon as I have it, there should be no privacy issue as all the data is just random auto generated id's really

Opps sorry

Hey,

here is a sample file from our school with sequential activity id's. I would really appreciate it if you gave the file a look just to confirm our format is proper. The file loads and runs in FET.

Thanks,

Daniel

Yes I think I got it now

My issue then is with my activity id's, right now I'm just using the auto id's from the database, will have to make a plan to generate the lesson id's in sequence and map back to the database id's later.

Thanks for your help.