The "Back of a Napkin" Plan: It is the source of entrepreneurial legend and lore, the million_dollar idea that was hurriedly scribbled on a bar napkin. Yet, for most potential business owners this option for business planning remains a fantasy. However, like any myth there is a tiny grain of truth inside. A quickie business outline can work as a launch plan under the right circumstances.
Another consideration. Should the business plan be a document that is focused on selling an idea for a product or service? For many years I worked in a company that did not want anything in a business plan that could be construed as showing a bias towards or against a project. The mantra was to only present facts in the business plan. The Operations Research Department was there to review the analysis as being unbiased. To handle the "what if" scenarios or sensitivity analysis we prepared a supplemental analysis documents which were mostly financial oriented. Personally, I like a factual approach and use the presentation of the final document to point out the conservative aspects of the content.