Hi,
I'ma software and syst3ms architect- from the corporate world. Used to doing very large and complex diagrams - for various super-large projects ; usually using UML, and IBM Rational Rose etc.
I now provide freelancing services to folks like you, but yourbudget is rahter low.
Nevertheless, can you tell me what exactly you need- , ni relation to the content in the attached document(which is quite well done by the way).
I'm a retired engineer and teacher (too)
Thanks
D.M.K