We like to think of this type of writing as up-front writing. Some people call it conceptualizing, some call it design. People are not trained to think of writing as an up-front, before you begin sort of undertaking. But up-front writing is one of the most cost effective sorts of development efforts you could ever undertake. Or, we'll work with your people, in-house, to facilitate the job.
Writing is never the whole job.
But it is a crucial part of the job, often the part that holds together the seemingly unrelated and cross-purposed people and things that define your project. It is a part that Common Noun excels at.