90, 7, 3 rule

Few days ago, my boss told me a rule in software projects (or maybe other projects).
The rule called 90, 7, 3 rule ! which means:

90 percent of project is thinking
7 percent is implementing
and
3 percent is debugging

isn't it fantastic ?

Maybe some developers do vice versa!

I hope we were not who developers that did 90% implementing, 7% debugging and 3% thinking!