What software can help me track and make diagrams for financial
justification of systems, hardware, software, and employees that show
dependencies. If upper management wants to cut a particular database
server because the support contracts cost to much I'd like to show
them a diagram of what: systems would be affected, users would be
affected, and who the proponents were. If they want to cut an
employee's contract, I want to show what customers and services will
be affected.

I am a software developer and have created a system that does some of
this but it is not good enough. If there is no good software to do
this, I may attempt to create a dependencies mapping web program. I am
imagining adding objects with descriptions and adding dependencies
with descriptions but haven't figured out how I might group objects
and/or have levels of object details so the whole thing doesn't end up
as a spaghetti web with only a search box to partially save it.