SWCV?

I am trying to understand how I should use SWCV.

While creating my design objects in IR, I import the SWCV from SLD.. How do I assign the SWCV and products in SLD? Should this be assigned to all of the impacted Technical systems/ Business systems? For example, if I have interface to send FTP from R/3 to Outside system, to which of the Technical / Business systems should I assign my SWCV?

Thanks in advance