For example, let's say you had a concrete pour that went ok, ask yourself:
Why was it just ok?
It took longer to pour out, then expected.
Why did it take longer than expected?
Because the finishers got behind; it took them a while to get the concrete placed.
Why were the finishers getting behind?
They concrete was stiff on the last half.
Because the trucks were starting to back up and the concrete was getting old.
Because we were still working on the slab prep (rebar placement, recess areas etc..) in the morning, while the pour was going on, which caused the finishers to wait on us at times.
Why were you still working on slab prep?
Because the area was not turned over until 3:00pm the night before.
Why was the area turned over late?
Because the dirt contractor was behind schedule.
Why were they behind schedule?
because he did not show up on Tuesday.
Why did they not show up, did someone forget to call them?
No, they were scheduled but decided another job was more important.
So after they were a no show what decisions were made as far as schedule and the pour date?
We had to make the pour, so we waited for them to show up the next day and went back to normal, just trying to get it done.
Because the finishers were not able to get the slab placed quickly with fresh concrete they had to work twice as hard to lay it down, because the carpenter crews were still placing rebar and fine grading the gravel, because the area was not turned over to them as scheduled because the dirt contractor did not finish on time because they were not on-site on the day they were supposed to begin the prep. So you can see one missed step cause a chain reaction of events to which caused the un-productive slab pour. If we focus on the problem at the first or second why we will never get to the route cause and will learn only half of our mistake. The problem is decisions not being made right then, whether it's changing sequence of flow (maybe focusing on one area, a certain section so that one half was completely ready for the finishers when they show up, instead of nothing being ready and work needing to be done in all areas).
Once a schedule disruption happens, an action item needs to be implemented.
It's like concrete trucks stacking during a big slab pour, you're trying to hurry and pump old, dry concrete before time expires. However, this will cause a chain reaction with stacked trucks behind the one currently being placed, whereas if you remove one of the old trucks from the lineup the next truck will be fresher with more time to place out and so forth down the line.
Flow is what we are trying to achieve to be productive. Every time there's a delay, well this disrupts the flow. So asking why allows us to find and get to the root of the problem. Why is a powerful word if asked continually it will only help you learn and grow.