Maybe it's okay as an assignment for an MBA class, but it would be just too confining and irrelevant for today's fast-paced business environment. Anyway, you're ready! You've thought about this business venture for a long time and talked it over with friends and everybody agrees it's a great idea. Best to strike while the iron is hot!
"Plans are useless; planning is indispensable," according to Dwight D. Eisenhower, then Commander of the Allied Forces in Europe during WWII. Now, you may be in total agreement with the first part of that statement, but you are really not convinced of the truth of the second part.
Carrying on with the example of a coffee shop, a business plan consultant will figure out what the best location would be. They already know coffee shops do well in areas with a certain demographic in place. These include students and workers, who are within close proximity to book stores.
Small business consultants are very much on top of their game. They compile industry reports relating to the business, conduct feasibility studies, as well as studies relating to potential customers.