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.
Planning out your business on paper first gives you long_term benefits with potential investors, employees, vendors, and suppliers. The business plan becomes your roadmap to success, with pertinent data that shapes the course of your business start_up and lets you adjust your journey as contingencies arise. Business planning templates are readily available and data sources abound at your fingertips. You will achieve a solid understanding of your business as you work through each section of your plan.