Business planning is a key part of creating a successful business. Planning helps you assess how good your business idea is and decide what the best way is to make things happen.
Planning lets you think about what you are going to do and anticipate mistakes. If you don't plan, your only option is to learn as you go along - often at high expense.
Effective planning helps you develop a business strategy that takes into account what you are trying to achieve and what competitive threats you face. A realistic strategy will take into account your own skills and the financial resources you have.
Whether you need to raise start-up financing or not, you should write your strategy down as a business plan. Doing this helps ensure that you have thought through all the important issues in a systematic way. Your plan then becomes a working tool that you can use to help you run the business, revising and updating the plan over time.