This means that you prove the viability of your business, show that you understand the market, and have a detailed strategy in place.
The length of your business plan fully depends on what you intend to do with it. From the SBA and traditional lender point of view, a business plan needs to be whatever length necessary to fully explain your business. This means that you prove the viability of your business, show that you understand the market, and have a detailed strategy in place.