You do this step to make sure that you are profitable. You do this step to make sure that the sales you generate produce a profit. Prepare a budget/projected income statement and a cash flow statement. If you do not know how to do this then hire a part time CFO.
If you want to get more elaborate with your business plan because you are looking for funding then take the components of the executive summary and elaborate on each point. However as I previously mentioned in a previous post if you are doing a business plan to use as a working document you only need the executive summary, marketing plan and financial plan.
Here is the thing. Without a plan of how you are going to execute this new business you will be wasting a lot of time doing a lot of things with no direction. If your initial plan is not working then change your plan. It is ok to change your plan. That is the beauty of a business plan. The most important reason to have a business plan is to have a working document! A business plan isn’t something that you prepare once and then throw in the drawer. A business plan is not a relic. A business plan is something you need to keep you on track, to make you productive and to change when necessary. Very rarely does an initial business plan work. Many times the plan changes multiple times. This is OK! When you are starting a business you must develop a rhythm of going about it. The business plan gets you into a rhythm and I promise you by doing it you will re-discover things and create new ideas. The other reason you should have a business plan is your bank. Bankers love to get business plans. It reinforces what your banker already knows about your business and if you made the mistake of not explaining your business to your banker then the business plan will serve as a document that explains your business to your banker.
