May I speak frankly? We leaders get frustrated with annual plans because (1) stuff happens that no one could have anticipated, and (2) we are fearful of being held accountable to a plan we created with imperfect information. Far too many of us build an annual plan, file it away, and (maybe) don’t review it until the end of year performance review time, or when we need to create an end-of-year report.
In short, we go through a planning exercise because “we’re supposed to” rather than as a stewardship approach to leadership. You’re a better leader than that, so don’t let this year’s plan be wasted energy or a pro-forma exercise.