Here is one recent example of a Design Process model. It’s ostensibly for ‘Information Design’ — but could be for ‘Document Design’ writ more broadly. 
Like other Design Process models, the prototypes (in this case, legal or operational documents) would be based out of earlier steps of identifying the target audience & gathering insights about them.
Then some prototype documents are rolled out, and put in situ to see if the audience will use them and if they work correctly.
Then, after evaluation revise the prototypes, and keep testing and revising till the prototypes function well.
Once you’ve got something good, then roll it out more properly & broadly.
Continue the evaluation — but this time, with longer cycles, only going back to revise when really needed.
