How to get two subgroups share a common activity?

[Abou]

Hi, I have two different subgroups and i need them to have a common activity.  When i enter the activity for each of the groups, FET schedules the activity differently for each subgroup. I want both subgroups to have distinct schedules but share the same time, space and teacher for the common activity. Is there any constraint for that? Any help will be highly appreciated.

Cheers

[Volker Dirr]

You can add both groups/subgroups into a single activity. So you don't need a constraint for that. (you can use a same starting time constraint, but i don't recommend it if you need only one room for that. If you need 2 rooms, then it's better to use same starting time constraint.)

[Abou]

Thanks for the prompt response. To be clear, what i mean is i have two sub groups A and B. Students in subgroup A offer Physics Chemistry Biology and English, while students in subgroup B offer Geography, Economics, German and English. I want both subgroups to have their English classes together with the same teacher(TE) at the same time in the same room.

I tried to use the same hour same day constraint but FET couldn't timetable them because it interpreted it as double-booking the teacher(TE) since they are in different subgroups.
I then tweaked it by appending a '1'(TE_1) to the teachers name in sub-group B which seems to do the trick as i was able to use the same hour same day constraint. However, i forsee problems with this method as the teacher (TE) may also be able to teach other subjects and FET may schedule him/her at the same time with TE-1 since they are now interpreted as different people.

I'm sure their is a less cumbersome way of going around this . Thanks do much

[Liviu Lalescu]

I don't understand the problem. You can add two or more students sets to the same activity. So for the English activity add both the subgroup A and subgroup B.

[Volker Dirr]

exactly. and if you need to use the same starting time constraint, because you need 2 rooms, then you are must add the teacher only in one activity, but not in both.