Do It Tomorrow: A Diagnostic Procedure

I'm reading through the Do It Tomorrow book by Mark Forster...

From Chapter 12, "Completing the Day's Work"...

My own rule is that if I have not caught up completely within three days at most, I will initiate a diagnostic procedure....there can only be three things wrong: 1) You are not working efficiently. 2) You have too much to do. 3) You are not leaving enough time. [To remedy,] work in closed lists and batches of similar actions....look...at your commitments...leave a certain amount of time unscheduled during the week.

Have you read the book yet? If so, I'd like to know what you thought of it. Please let me know in the comments below this post.