I agree with @hm243 that although it would be time consuming to update the document every time a new revision is made, it would be necessary to update all the relevant documents. So as @hm243 mentions that if the Work Instructions reference a SPEC document and you revise the SPEC document you would need to update the Work Instructions where it references that SPEC. I think its necessary to do this so that documents are up to date and if you’re audited or hire new team members, all the documents are accurate and up-to-date. I haven’t had a role where I’ve needed to work with device documentation at this level, so I’m not sure how realistic it is to do this or that its done especially for small med device companies, but I personally believe that it should be done.