How to get around "It's impossible to have 3 or more subactivities consecutive"

Started by szachariah, May 17, 2024, 05:47:08 PM

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I am a first time user. I have put in over 100 hours learning to use this wonderful tool. A VERY BIG thank you to the contributors who make this possible.

My school's upper division works on a 45-minute block. I am able to generate timetables for them.

Our lower division works on a 15-minute block; some 30-minute periods, some 45-minute periods, and a few 60-minute periods.  I am able to generate timetables for them too.

We have a handful of teachers who teach across divisions, and a few rooms that are shared.

So I tried a 15-minute block to generate a whole school timetable. And I am running into problems.

Even if I create a timetable for just ONE grade, what was working in the 45-minute version doesn't work anymore in the 15-minute version.

In the 15-minute version, I have tried adding the time constraint "A set of activities has a set of preferred starting times" with weight=100. The starting times are at 45-minute intervals. E.g. 8:30, 9:15, 10:00. But this does not seem to help. I have also tried setting the weight to 0, and/or the Consecutive flag to blank. All to no avail.

Here is an example of my CSV
Subject,Total Duration,Split Duration,Min Days,Weight,Consecutive,Comments
Math-5,5,,1,100,y, this is the 45-minute version
Math-5,15,3+3+3+3+3,1,100,y, this is the 15-minute version

Do you have any tips for me on how best to implement a 15, 3+3+3+3+3 duration?

Thank you

Liviu Lalescu

Hello, @szachariah ,

Thank you for your flattering words! Over 100 hours of learning is impressive!

You should be able to use activities with duration 3, and your preferred starting times should be OK, and your CSV. Please send me your CSV files and fet file, so I can have a look (here, archived, if public, or by my email). FET will never put 3 or more subactivities on the same day if they have a min days between activities constraint, so it can put 3+3=6 hours on a day.

Also, in your first approaches, if a teacher crosses divisions, maybe you could use some constraints which were added recently, the constraint of type teacher(s) max hours daily in hourly interval. But I would prefer 15 minutes "FET hours" if possible.

Please let me know.


Thank you for your speed response, Liviu. I'll create the simplest CSV/.FET I can, to isolate the problem, and then will share it with you. 

Liviu Lalescu

You are welcome, szachariah. I'll wait, then. For CSV, I will need the students.csv and activities.csv (and maybe the rest of the CSV files, if you want).

If the initial file is private, you can send it by email and it will remain private. But I completely understand if you only want to send anonymous data.