When most people ask whether you've got a business plan or not they are thinking of the Assets/Liabilities/Income/Expense statements. That's a piece of the whole plan, but if that's all you're relying on then you've bought into A LIE.
Full blown business plans are useful in an Eisenhower sort of way -- Plans are nothing; planning is everything.
What is often most important is to go through the process of identifying your destination (outcome goals), identifying what you need to do (planning), and identifying how you intend to do it (process goals).
Just walking through your typical day in your dream life can make a world of difference in whether you want to really reach that goal or not.
Many people get stuck on setting an outcome: "I want to be a millionaire." A few get as far as a plan: "flipping X houses a month." Very, very few think through the day-to-day process: "I will call # of home owners a day with a cheerful attitude and ..."
So, while the typical formal business plan could help a start-up get VC funding, an arbitrary small business owner is well advised to work on a lifestyle planning process in addition to the usual A/L/I/E business planning.
Whether you have a formal business plan ready or not, check out what I share (a "secret") for how you can save time, energy, and money. (I say "secret" because you probably already know what to do -- the question is: are you doing it?!)