I mentioned the financial aspect of a plan earlier, so let me add this. Another fact about financials to consider: not all business activities are about making money. Point being, in most enterprises financial considerations are centric to the document. But there are some other considerations. For example, a few years ago I wrote a plan for a new subsidiary that was focused on developing an inventory of patents. The potential financial returns were years into the future. Those patents may or may not ever have commercial value. Another example is a non_profit enterprise that has need for a complete roadmap for growing their profile in a market, of which a marketing plan would be the centerpiece.
A business plan contains several main elements. First, it lays out the mission and the goal of the business. The plan will spell out whether your company is in business to serve a greater good or simply to fulfill an unmet need. Determine whether your business will serve other businesses or supply products to consumers. These are all important elements that should be included.