Don't Make Assumptions About Customers ; To be an entrepreneur does require plenty of self-confidence, sometimes almost a bloody-minded determination to make your business work. But this confidence spilling over into thinking that you know what 'the market' wants can be dangerous, without checking that it's true. You need to do your research that the market does ultimately want what you will be offering, whatever products or services you will be selling.
Drawing functional Plan: After positive result form the feasibility study, functional plans are drawn up. Some scholars and writers prefer to include feasibility study with functional plan but the two have been taken separately. Whereas only after the feasibility study can one go into the derails of drawing up functional plans which would determine the strategies for all the operational areas : marketing, Finance and production.
When I have received business plans, the very best responses come from people who have looked at the risks and have an answer for every question. What you never want is to throw a scenario at your plan and have to answer "I don't know what I would do in that situation". You want to plan for every possible contingency, and certainly all the major risks to the ongoing success of your business.
I say that because of course you need to be careful with commercially sensitive ideas, as you do not want to pass your plan on to someone in the pub who then starts your idea before you across the road.