Don't Make Assumptions About Customers _ To be an entrepreneur does require plenty of self_confidence, sometimes almost a bloody_minded determination to make your business work. But this confidence spilling over into thinking that you know what 'the market' wants can be dangerous, without checking that it's true. You need to do your research that the market does ultimately want what you will be offering, whatever products or services you will be selling.
If a document needs to be developed that requires input from other disciplines_Finance, HR, Property & Facilities, Marketing, Procurement/Supply Chain_ then most likely you are looking at a team building effort to get the job done. In any event, don't look at the task as only as a roadmap that leads to a profitable product or enterprise. Business plans are a great way to build team buy_in, force a thorough review of options, define objectives, establish benchmarks to judge performance, and help arrive at a plan_of_action. Ultimately, it can lead to a Project Management approach to implementing a plan and that can be as involved and detailed as is necessary.