I'm looking for any papers, or books which explicitly outline software supply chain / value added map.
What I'm specifically interested in is a confirmation (or a rejection!) for an assumption that purely software development service oriented companies are lower in the value added map (upstream), the same as to see other modes of software businesses mapped in relation to end products / SaaS, etc.
Any of you stumbled upon anything like that? Might be I simply can find proper keywords to find what I'm looking for, or is it even too obvious to put it in writing? :)