Activity concurrent with one of three other activities

[math]

Hi!

I'm creating a schedule for the next semester and I'm not sure how to model the following:
I have a three actitivies (e.g. exercises): Activity A for student group A, activity B for student group B and activity C for student group C.
Each group constists of approx. 25 students.
Now we have another student group (let's call it student group D) with only 3-4 students. There's no point in scheduling a separate exercise for these few students. Instead, they shall join one of the activities A-C.

Is it possible to create an activity D for student group D and specify that it shall be scheduled in parallel to activity A, B or C? (i.e. same staring time day+hour). I don't care which one is chosen, I just want to have activity D to be in parallel to either A, B or C. FET may choose whatever fits best.

Is there a way of defining this in FET?

[Liviu Lalescu]

So the method from https://lalescu.ro/liviu/fet/forum/index.php?topic=3687.0 does not work, because the duration of the activities might be greater than 1 and because the activities of A, B, and C can overlap?

[Liviu Lalescu]

It seems that it cannot be done with the official FET. Maybe as a customization, but it seems quite difficult.

[math]

Hi!

The linked posting does not match to this problem. In the other posting I had activities A (3 hours) and B (1 hour) and I wanted to have activity B planned within the timespan of activity A.

Here I have four activities A, B, C, D, all 1 hour long. A, B, C are planned as regular activities. For example: Activity A is scheduled to Monday 10am, Activity B to Tuesday 10am and activity C to Friday 10am.

Now I would like to specify that activity D is planned to one of these three timeslots. This means that EITHER activity A+D have same hour+day (Monday 10am) OR activity B+D have same hour+day (Tuesday 10am) OR activitiy C+D have same hour+day (Friday 10am).

In FET it could look like this:
Time -> Activities -> Activity has same starting time as one activity in set

When adding a constraint in that dialog, I would select my activity D in the top of the dialog in a dropdown combo box.
Below the combo box I would select activities A, B and C from the list of all activities (just like selecting a set of activities in "Set of activities has same starting time").

From the planning point of view FET could translate the new constraint by first trying to plan for same starting time of activities D+A. If this does not succeed, it could try for D+B etc.

Basically this is exactly how I'm solving this problem at the moment. Even though it's just a relatively small number of combinations, it's quite an effort to do this manually. That's why I was asking if it's possible to realize it automatically with FET.

[Liviu Lalescu]

It is not easy at all to add this new kind of constraint in the algorithm (In the interface it might be easier).

However, if you know that the activities of A, B, and C are not overlapping, you can use the magic constraint activities occupy max time slots from selection. Activities = A, B, C, and D, selected slots = all slots of the week, max occupied = 3.

If A, B, and C can overlap, the constraint might not work: you can end up with A and B simultaneous, and then C and D on other times.

[math]

Excellent idea, thanks a lot. It's impossible that activities A, B and C overlap (since the same teacher is assigned to all activities), so your suggestion should work perfectly for me.

Thanks for all your support! :-)

[Liviu Lalescu]

I'm glad it works!