The length is not important. The essence of an effective workable plan is design and execution. Looking into the future is risky. Yet, management must look forward to plan for change. The company must grow to survive.
Growth comes from change.
In looking to the future, management is planning how the company will change to grow. A business plan is the distillation of management's thoughts, strategies and vision for the future. A business plan serves a variety of purposes. It provides a frame of reference for operational decisions. It provides information to prospective investors.