Well planned, half done
It is said that well well planned is half done. Good plans are important to any task, but is it better to have perfect plans or getting something done?
No matter how much you plan it won't make anything ready. There is also always things that are impossible to plan ahead. You can only plan for the unexpected, but those surprises need to be handled as they appear. Unless you want to get back to the drawing board every time it happens.