Double-lessons preferring certain slots

[alexwonglk]

Sorry for repeating this theme if it has been raised before (which is very probable!)

Is there a way to ask FET to prefer scheduling activities with a duration of 2 in certain slots?

To be a bit clearer, there are 7 lessons a day in my school. Various subjects have double lessons in various grades. And I hope either

(a) most double lessons are in lessons 1-2 or in lessons 6-7, or
(b) most lessons 1-2 and lessons 6-7 are double lessons.

I believe there is a subtle difference between these two. So any suggestion or clever workarounds that can achieve either of these would be great! (I would prefer version (b).)

This is what I have tried and am quite satisfied with the result already: As there are two teachers who only have double lessons, I have marked them unavailable in all lessons 3-5. I believe this has already sped up the generation by quite a bit, and have put around 60% of the double lessons into my preferred slots. What are your thoughts or better suggestions?

[Liviu Lalescu]

Hello,

No problem for repeated questions! (and it is not repeated.)

It is an interesting question! Maybe you could use the constraints of type activities occupy max/min slots from selection. Add more constraints of these types, maybe for max, a kind of inverted one. For one constraint, add all activities with duration 1 of a teacher or of a students set (but not both), select all 1-2 and 6-7 slots with X (red), max occupied = an approximate value, which you will decrease with time, as you find new timetables. Or you could try with the other constraint, min.

Or maybe select with X (red) slots 1 and 7, min occupied = a corresponding value, with selected activities = double lessons of a teacher/students set.

Or you can develop your own method based on my approaches above.

[alexwonglk]

Hi boss! Thanks so much for the quick reply (and for the whole software which has been all too helpful!)

Giving your suggestion a try - and realise it would be a good feature in future versions that we can filter by the durations of sub-activities in constraints windows   

[Liviu Lalescu]

You are welcome! You can call me Liviu, if you want

I will add your suggestion in the TODO list, but I think there is not enough space for that.

I have a better idea: add two activity tags, Duration1 and Duration2, and you can add a tag for a whole selection of activities with a single click (in recent FET versions). You can then filter by tag.

[Volker Dirr]

Liviu, I think your idea is only a workaround, but not better.
You need to add such a tag to every activity. That is much work.
It will flood/increase the number of tags.
It will also "double" data. "Doubling" data is always bad, especially because you need to modify the duration sometimes and then there is a high risk that you modify the duration but you forget to modify the tag. It will be very difficult to locate such a bug.
So I think it is a good suggestion for the TODO.

[Liviu Lalescu]

OK, Volker, I will also add your words.

However, you can filter with an advanced filter the activities, and add a tag to the selection with a single click.