It's like planning backwards. 1. Determine what you want in life 2. Figure out what your business would need to do to give you that life. 3. Figure out how long it would take you to reach it. 4. Figure out how big of a market it would take each of the years you're planning for. 5. Then see if that market is big enough. Isn't this a much better way to go about planning your business? Shouldn't your business be designed to give you want you want instead of you working yourself to death just hoping for the best?
The main thing to remember in this section is not to provide new data, but to explain in detail data that has already been provided and to provide the support for that data. When you sit down to compile all of the elements of your business plan, make sure you have each section able to stand on its own merits. This means you should not reference other sections sending the reader (your potential investor) back and forth between sections.