You can concentrate so much on essential financials and supply logistics, but overlook other issues like marketing or opening times. By showing the plan to someone you trust, they can have a look and see what might be missing or worth developing more. Getting that valuable second opinion on how robust your idea is will put you in a much better position to start and keep going successfully.
Be Prepared For Risks : It is a fact of life that any new business or enterprise has a degree of risk attached to it. Therefore it is important for your business plan to analyse and calculate that risk, showing how you will engage with it. There is no business plan out there that is risk-free, but very often where the risk is higher then the rewards will be as well.
For any organization, various functional plans-marketing, financial, human resources, production-have to be laid down, even though all the functional plans serve different purposes and all theses plans provide guidance and structure to the successful running of the business.
That is a great thing to make sure you have in your business plan, that your business will be built around those real customer wants. Do not make callous assumptions, or statements like "I know what people want", "People are going to love this", and so on.