Director / Writer Christopher McQuarrie was brought in to work on Rogue One: A Star Wars Story to polish the script after scribes Gary Witta (The Book of Eli) and Chris Weitz (Cinderella, Antz) finished up on it. The whole thing comes from a concept brought to the table by ILM’s Chief Creative Officer John Knoll.
According to website Birth. Movies. Death, “Christopher McQuarrie, one of the better writers out there, and a guy who has been called on to quietly fix major motion pictures before (most famously: World War Z). According to my sources McQuarrie came in fairly early during shooting and used his Usual Suspects / Mission: Impossible skills to tighten up and fix this heist story set in the Star Wars universe.”
You can read more of their article here.