Where to push stop?

The last few weeks, I am working a lot from home, preparing for PairCoaching.net
When I work at home, my eldest son comes into my office to get me for dinner, or ask me to play with him.
Most of the times, he asks, daddy are you coming.
Last week, I really wanted to finish something before I [...]

What would I need the five Why’s of the Toyota Way for?

I did not follow the Toyota way session at XPday London [Sorry Pascal], so I did not have an answer to my trouble with the five why`s. My question is, what is so good about the five why`s in lean?
As a coach I prefer using specific questions like:
Who
What
How many
When
And not why.
Why is the question my [...]