Why was it just ok?
- It took longer to pour out, then expected.
- Because the finishers got behind; it took them a while to get the concrete placed.
- 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.
- Because the area was not turned over to us until 3:00pm the night before so we could start working on it.
- Because the dirt contractor was behind schedule.
- because he did not show up on Tuesday.
- No, they were scheduled but decided another job was more important.
So after they did not show up, 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.
By asking WHY you can see that the pour production was subpar. 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 stacking concrete truck. 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, with remaining trucks. Flow is what we are trying to achieve to be productive and everytime there's a delay, well this disrupts the flow. So asking why allows us to find and learn from the route of the problem, as to not impact the remaining chain of events. Why is a powerful word if asked continually, will only help you learn and grow.