I've been writing without much plot work lately, but being able to move scenes around and see things from a broad perspective like this allows me to stay on track or to visual something that I might be having a problem with. Some writers use sticky notes, dry erase boards or cards. Whatever works for you. I like using the cards and then setting them out on the floor. And sometimes I make up cards after writing the rough draft, so I can see what's happened overall and check pacing, subplots, etc.
And using this method is really great for book proposals, when you have your partial but you need a finished synopsis to show your agent or editor how the book will progress and end.