Does an entrepreneur goes through all these steps to become an "entrepreneur"? In other words, does a business plan that important?

ENTREPRENEURIAL PROCESS LO1 The process of starting a new venture can be referred to as the entrepreneurial process. The process involves four specific stages: (1) identification and evaluation of an opportunity, (2) development of a business plan, (3) determination of the resources required, and (4) management of the business. Although the stages proceed sequentially, no one stage is dealt with in isolation or completed before work on the next stage begins. For example, some elements of evaluating an opportunity complement elements of business planning. We will deal with ideas and opportunity evaluation in this chapter and look at business planning and the other elements in the entrepreneurial process in subsequent chapters. Page 56