This is a wonderful method to break down projects. I might have done much better in college if I had used a project management tool like that.
In the work force, I did something similar, but not as formal since my projects had their own structural breaks. Other people tried to work through such breaks, but I never did. I never had a project fail.
There are other advantages. When training new programmers, I gave them a small assignment and told them to work on it for an hour, no more. Then, we would get together to discuss it.
That gave them enough time to see the problems, not enough time to get overly frustrated, and they had much better questions to discuss than they would have had at the beginning.