But your fixed expenses don't do this. They remain the same no matter what sales does. That's why it's call fixed. These are expenses like rent, taxes, utilities, phone, salaries, insurance, etc. A lot of business owners never consider this. They just lump all their expenses together. But you could never make an accurate plan if you combine all your expenses together. If you project your sales higher and want to know what your expenses will be, you have to separate your fixed and variable. So, thinking about this principle, let me ask you a question. If your sales grew 10% and nothing else changed, would your profit margin be higher, the same, or less? Profit margin is % of profit against sales
What should come into your business plan is how you assess it, how you foresee anything occurring that could have an adverse impact and how you would deal with it in the right ways. If you are looking to obtain funding from a bank or people you know, it is essential to show what the risk factors are in the proposed business and how you plan to defend against them.