How to make a proposal to improve the workflow?

Question

ERP

I got a job writing proposals for the creation of a corporate network, the introduction of workflow, videoconferencing (the organization has branches), the personnel system in general. How to draw up can there be any standards?
I also wanted to know what such drawings are drawn on, because the boss, far from IT, wants to present them visually + textual support. What program is used to draw such graphs?