All of your resources will be allocated accordingly and your decisions about operations will point towards achieving those goals. You will also align your organisation in a way that will drive people and processes to work towards that plan.
There are few reasons why strategies fail, and one of them is because the business landscape often changes. Technology, competition, markets, disruptors just to name a few mean that businesses should constantly take stock of how they are performing throughout the year against their plans.
Another reason is that some small businesses are too busy managing the day to day operations of their business that they fail to look at and understand the key financial drivers that are fuelling growth and profitability opportunities for the future.