You can find a sample business plan for a small business in all kinds of formats. There is a sample business plan for a small business where you basically fill in the blanks or you can have access to a sample business plan for a small business where you can pattern yours from it or you can develop a business plan that is centered on what you want for your dreams and your life.
A plan like this would show you how much sales your business would need to do, what your fixed and variable expenses would be, what your material cost, labor cost and profit would need to be to provide the income and profit margin you want. You can see pretty quickly if it's possible for you to get your business to that level. I don't know of any better way than to have your business give you the income and profit you want. What's neat is you can determine what you want your income to be and your profit to be over the next few years and develop a plan that can show you exactly what your business would need to do to give you that income and profit.