If you don't know where you are going (i.e. have a roadmap), then how do you expect to get there? Running, expanding or starting a business without a business plan is like trying to drive from New York to Chicago for the first time without a roadmap or MapQuest! Planning gives you a path to follow, otherwise, you are just guessing. In running or starting a business , the learning curve is short before you run out of resources and are forced to close. Therefore, a business plan helps you set up a sound framework, model and system ahead of time, as well as, address potential problems and threats, so that you can capably run a business . If you don't have a system in place to deal with problems and you don't have a sound strategic plan in place, you will find yourself needlessly sidetracked by working "in" the business instead of "on" the business .