SolidWorks 2013 gives you the ability to make envelopes from subassemblies. Workflow improvements include designating components as envelopes as you insert them into assemblies, and changing components to or from envelopes at any time. New options let you adjust envelope visibility and load envelopes as lightweight or read-only.
You can visit our new SolidWorks 2013 website to see all the major updates when it launches on September 10. In the meantime, if you want to learn more about how SolidWorks can help your business, check out the videos in our demo library.