A good plan is not only about writing down where you are and which steps are required to get you there.
A plan typically needs to be changed, remade, modified, sometimes even erased and started from scratch. It tailors to the new components that come into the scene. If something bad happens, the plan is updated. But the same happens if you get some good news. Each day it gives you a new perspective based on the dynamic world we live in. It is not meant to be time consuming, it is simply a habit you develop along the way in order to be more prepared to take advantage of the opportunities you were looking for.
A good plan is the one being taken care of. The one that embraces change, now and ever.