Having a vision from the start about where your business will be heading is important. While most entrepreneurs will admit that their business plan in the beginning was not an accurate map, few investors and other advisers are keen on you not having a a focus. A business plan is still an important tool to launching in most industries.
There is no way, unless you are clairvoyant, that you will be able to predict the changes in your company, industry, or the economy. Too many variable exist in the real world. Engineering is an exact science that requires perfection in the plans and execution or buildings and bridges will collapse. Entrepreneurship is the opposite, often needing heroic bending of rules and other flexibility to achieve success. (I am not saying engineers cannot be great entrepreneurs, or vice versa, but to do both can be a stretch for some).
Someone who started a business in 2008 would never have realized the pending recession, nor could they have predicted the severity. Their plan would quickly have become obsolete, but their vision for the company they were building would allow them to better navigate the tough decisions. When you think about your plan up front, be sure to imagine multiple scenarios, event though you can never assume all that can and will happen.
Growing a business often takes more time and more money than you anticipated, even with the most realistic planning. Be prepared to extend, maybe double, your needs. If your upfront projections calls for three years and $500,000, consider what you will need if the reality is six years and $1 million.
Know going in that you can easily get buried with the small things, and be conscious that you cannot spend your time picking up pennies while stepping over $100 bills. Commit early in the process to putting your energy into activities that allow you to grow your business and not the things that will take you away from the goals. Investing your time in insignificant and "small" activities will derail you success.
How you begin will have a major impact on how you finish. Invest the time to plan and prepare for ample time and financial resources. While no amount of up front planning will eliminate the obstacles, you will at least be less surprised by the hardships when the occur.
Have A Great Day