I assume you mean create a component in an assembly?
In WF2 the short answer is no...but you can insert a component with basic geometry and edit it within the assembly, using references from other components in the assembly.
I wish it was possible, I could have done with it quite a few times.
It is possible in Inventor and it's very usefull.
If anyone knows better I will be pleased to be corrected...
Save your assembly as IGES flat state. Then open the IGES as a part. Shrinkwrap is good for small and very simply assemblies and you need to set the accuracy to maximum.
We should apologize to 427 for hijacking the thread ...
Perhaps, Hydro, you should elaborate because I'm apparently not understanding something. What happens if you (menu) Insert -> Component -> Create ...? A ``short answer'' indicating you cannot create a new, empty or with default datums or whatever else you may have in the template part (or assy for sub) component isn't balancing out. Maybe some config opt that I've long ago set and forgotten? Are you using start part and assy templates with first features in them?
Back on topic, 427 really should reveal the intent. Merging assemblies into a single solid part has some uses, I suppose, but there are probably more effective ways to accomplish most desired goals (?).
The need I have for this is...a die cast part with molded in arm..(created as a proe asm. die and stamping) now want to machine it.What I did was create asm. and assemble the asm. this allows me to remove material and remains parametric.
