The most important aspect of business planning (the "What does it all come down to?" part), however, is spending the time to do your research ("due diligence") and critically thinking about these various aspects of your business. Of course, it is impossible to anticipate every detail simply by spending time thinking and writing; it is for this reason that plans are referred to and viewed as "dynamic". However, the more issues and scenarios you are able to come up with ahead of time, the more prepared you will be to handle these as they arise.
Financial Planning : Perhaps one of the most important parts of any business plan is the financial plan. You need to make some forecasts of revenue and expenditure over a period of several years. You can then estimate when you will reach a break even point and how much profit will be possible in the future. Set out anticipated monthly cash flows in a spreadsheet program on your computer. As businesses often don't grow as fast as their owners expect them to you should outline several scenarios. One scenario can show your expected outcome, one can show a more optimistic forecast and the third one can show a worst case scenario.
It needs to have a list of everything you need. Note that the word everything here comprises of the equipment, technology, raw materials, financial and other resources that you may need when starting and running your business venture. Having all these listed will give you an idea on how much capital you need before you start and how much money should you make in a day to make your business survive.
A plan may be essential in order to prove that your concept is viable when it comes to talking to investors or seeking funding from other sources. However, even if you are independently funded and have nothing to prove to anyone a plan will still be useful. It will help you to confirm that your plans are indeed possible and it will give you a place to compile all the data that you collect from your research.