Planning Workshops
 

I have to include a number of one day workshops in my project plan.

Each workshop will have different members of the project team involved and each member of the team has different 'off hours' setup. ( It's summer everyone is going on holiday )

I cannot find a way to do this, as tasks are assigned to [I]any[/I] rather than [I]all[/I] required resources.

It then either changes the effort or duration to match the change.

I'm sure there must be a way of doing such a basic thing so I must be missing something.

Short summary: How do I make a task require _all_ resources for it to be scheduled.

Thanks