Resourse planning and scheduling

Hello all,
I just started to see different features but I don't find a module that make possible the planning and scheduling or several resourced involved on project.
I would like to have the possibility to see all resources commitments and then try to optimize them but at same time moving tasks from one resource to other one and see the impact on delays or on dead lines. 
There are some tools that make possible to use drag & drop and move easily activities seeing contemporary the effect on timeline etc. etc.
Is it true that kind of feature here are missing ?
Thanks