Hello everyone.
I have the following situation.
I know that my timetable is unfeasible grouping all the activities 2 by 2 with the activity "split + duration" for example 2+2+2 in 3 days etc ... (i'm assuming that split+duration is hard 100% right?)
or if feasible it cause teachers GAPS increasing too much (6, 7, 8 ... per week)
But i don't know how much i've to give up with 2+2+2 in favor of 2+2+1+1 and for how much teachers ...
Can i let the algoritm to find the right balance?
My goal is to let FET tending to reach more 2 by 2 as possible, so maximize them, mainteining teachers gaps down the chosen bound (and still minimizing them)
For example supposing max weekly teacher GAP at 4 we will have:
- when teachers schedule 2+2+2 cause 5 GAPS (forbidden) -> one 2 block is splitted in 2+2+1+1 to reduce GAPS
- 2+2+2 and 4 GAPS is ok
- but 2+2+2 and 3 GAPS is better
- and 2+2+1+1 and 2 GAPS ?? (school have to choose if priority are blocks or gaps -> % constraint ? )
- 2+1+1+1+1 is forbidden (teaching needs)
Can we reach this behaviour?
Thanks you very much!
Andrea Canton
Hello, Andrea,
Yes, split+duration is hard 100%, as you say.
In FET, you can only fix a max value for gaps, with 100%. The only way to minimize the gaps is to start with a large value, and lower it if the timetable is still possible.
You could:
1) Add activities A1(2)+A2(2)+A3(1)+A4(1), min days between them = 1 with 0% and consecutive if same day = true. Then add separately other two constraints min days between activities: A1,A2,A3 for the first constraint (then respectively A1,A2,A4 for the second constraint), min days = 1, 100%.
2) Add a constraint two activities grouped: A3,A4, 90% or some suitable weight (less than 100%).
Hello Liviu.
Uuu smart!
It will work fine.
Tkx
Andrea