It's more that software is already so unpredictable. A 90% confidence estimate for a task might be 4 hours to 4 months. That's not very useful. Counting routine

It's more that software is already so unpredictable. A 90% confidence estimate for a task might be 4 hours to 4 months. That's not very useful. Counting routine work would increase accuracy to something like 2 days to 4 months. I'm not sure if it's better, but we can make some plans around that. The extra control is a little comforting. And it's less demoralising when it's not done by the end of the day.