I believe business planning is important - but not every plan needs to be a formal one.
I write a new plan each year, and the plan answers all of the basic questions I need to operate successfully.
What do I do?
Who do I do it for?
What are my annual goals?
How do I plan to reach them?
What are my financial goals, and how do the link to my activities?
How will I reach new clients and continue to better serve existing ones?
I think a business plan works best when it is a "living document" that you turn to often for revisions and tracking. Some people operate just fine without one, but I think for most of us written goals are more likely to be achieved than those that float freely in the mind.
My 2 cents anyway.

