Prior to writing your business plan, take time to focus on two primary goals: What you see as the objective and future direction of your business and what you envision as your final business plan.
The goal or future direction of your business. By identifying where you see the business moving in the next one, two, or five years, you can write a plan that adequately reflects your goals. Your personal skills, needs, knowledge, leadership abilities, available resources, level of risk, and the nature of your business factor into the equation when identifying your personal business goals. One of the most important aspects of starting your own business is that it gives you an opportunity to do what you enjoy. If your goal is a two-person business, then that is what you will reflect in your business plan.
Conversely, if your goal is to build a large corporation, and you realistically feel you have the knowledge and experience to do so, then that is what your business plan should indicate. There is no minimum or maximum length for a business plan. The determining factor for length depends on the level of details and the amount of funding you require to achieve such goals.