People often want to know if they really need to draft a business plan. The answer is yes. Creating a business plan is an important exercise for new and established business alike.
And yes, I know you are not looking forward to it. I have written three business plans over the years and I know that writing one is time consuming, a lot of work, and a sometimes frustrating process.
The first two times I did it, I drafted the plans from scratch, using models that I had read in books. They were fine business plans, not great by any means, but serviceable. Certainly the process of writing the business plan was very valuable. Doing so lets you think through the venture carefully, helping you to avoid problems before you encounter them.