I came across a simple, but excellent example of process graphics in Michael Bierut's new book, How To. Above are two pages from the printed brand guidelines for the design of United Airline's once low cost sub-brand called TED.
As part of the design and branding work, Michael's firm Pentagram wanted to show how the different divisions of United Airlines all fit together. Instead of a single visual ("process graphic"), they created two: one for internal audiences (on the left) and one for external audiences (on the right.)
This is a great reminder for me that one story does not always mean one single graphic. Think about your audience, think about their level of knowledge, think about what you want them to take away from your grpahic.
Below is the full page from Michael's new book.