or why commitment is impossible for a pro
There is a general problem with estimating the effort of an IT-task and therefore its finish, which in Scrum is called commitment.
That problem comes up, if you haven’t done the task many times yet. And in IT you haven’t done the task many times yet, if you haven’t done it many times yet in exactly the same way.
Now what does the IT-pro do, if he has a task, that he’s doing exactly the same way for many times? He’s going to automate the task and it discontinues to exist.
Hence, no pro can master his tasks in a degree, that he can make an honest commitment.
The ancient Greek Heraclitus‘ „panta rhei“ shimmers through this modern phenomenon in information technologies.
Everyone working with computers for a while recognizes that one day – most managers won’t:
You cannot step twice into the same stream.