Your business plan must be big enough to capture your vision, flexible enough to go from concept to maturity, and detailed enough that it represents a paint by number kit. Many business plans are designed to work within the limitations of the current team without a natural transition to the ultimate goal.  This means that when the first set of metrics is achieved, you often will have to start over with a new business plan.

Your plan should allow you to make money today!  Not tomorrow! Your plan should describe what you or your team can complete today with your current resources with your current abilities.  If your plan is too futuristic, remember that you must walk before your run and often crawl before you walk.

Every business must have a basic business model: make a product or provide a service, sell it and get paid.  The plan must enable you to do this once and then to replicate it many times. You know when your plan is done when you can show it to someone else and it is clear enough and simple enought that someone else can carry it out for you.  If there are too many things still in your head, then you are not done.