Soft-skill
Disclaimer: I look at it like this. It's arguable and others may have different prospect about it.
but not too much
If we missed a deadline or messed up something then being stressed about it will not help anything.
What is done in done? We can't do anything about it. What's in our hands is, 'what can we do next'? How can we prevent that in future?
What we can do in future is to communicate early & clearly
Failure is not a bad thing. If it happen once and you learn from it.
Experience is not the amount of days you are working, it's the sum of Failure you have in your career.
There are six steps in the original technique:
References