CS,

There's probably 10 different ways you could think of to manage new or updated requirements to a system requirements specification document. However, placing all of your new requirements in a separate document hasn't worked well from my experience.

It's typically difficult for a reader of the new and separate document to get a full understanding of the new requirements without the full context of the current spec and surrounding information. Jumping back and forth between documents to get this context is difficult.

If you are using MS Word for your documentation, consider using track changes and simply updating your documentation. Of course, it's always a good idea to have a revision history table where a summation of thew new changes along with who made them and when can be tracked even after the newly tracked changes have been accepted.