When you're writing a business plan in a situation like these, you need to address a few issues the intentional entrepreneur has already pondered. The first is do you really want this idea to become a full_blown business? Certainly it's flattering when you realize there's a market value for something you were doing anyway, but that doesn't always mean you should launch a business. A lot of accidental businesses form around fads or seasonal items, and may not be robust enough to function as year_round, money_making, enterprises.
Production Operation _ If a product must be manufactured, what is the process? Will the work be done on_site or subcontracted? Who are the subcontractor(s)? If on_site, what space, equipment, machinery, production employees are needed? What suppliers are needed? Who are they? How will quality be assured? What is the anticipated production output? What established credit lines do you have? Possible Data Sources: local Chamber of Commerce; yellow pages; trade associations.