Saving Large Assemblies

Good morning to all.

I am knew to this forum, so my apologies for any improper etiquette.

I just started a knew company which uses SolidWorks 2011 as its primary design platform. My first project is a redesign of an existing product assembly. My approach requires slight modifications to each of the sub-assemblies and there relative Part models. I would like to maintain the integrity of the original assembly in its original design configuration. 

My question is;

Is there a method, besides "File Save As Copy'" option available, which when conducted will uniquely save the Primary Assembly and also save each individual Sub-Assembly and its Modeled Parts as a new assembly in one single step. This would save me a tremendous amount of time uniquely saving each individual Sub-Component, while also providing me the reassurance, that any component design changes I make within the newly designed product assembly will not migrate backwards to assemblies sharing modeled parts.

I hope that I have stated my dilemma clearly, and would appreciate any responses.

Thank you  

SolidworksAssemblies