I am very serious. My clients respond very well because it helps them plan better. The problem with a traditional one number estimate is you don't see the err

I am very serious. My clients respond very well because it helps them plan better. The problem with a traditional one number estimate is you don't see the error bars so they don't know how to treat "3 weeks". My approach also helps start a discussion about how to reduce the size of the plus/minus bit, such as reducing scope, breaking into multiple pieces etc. And the minus bit coming to negative time works well too. It becomes a decision about using what is already there even if not perfectly suited versus doing the new work, and how much of it to do.