It turns out that we don’t know the procedure. We haven’t got any clue to just how difficult the procedure is. We aren’t computers. We don’t follow procedures. And so comparing the complexity of the manual task, to the complexity of the procedure is invalid.

~ Uncle Bob Martin from, http://blog.8thlight.com/uncle-bob/2012/04/20/Why-Is-Estimating-So-Hard.html

ɕ