Those of us dedicated to Lean learning know that Taiichi Ohno, the manufacturing genius from Toyota, was very famous for his Ohno circle. Stand in the circle, watch what is actually happening, and keep on asking why? He would normally do this for two hours with one of his students (group leaders). He would then show up and ask what the student saw. He would do this several times with a two-hour separation for an entire day. A great way to teach if you dedicate time to people development over process improvement.
I heard from Jeff Liker, the best-selling author of the Toyota Way, that he – Taiichi Ohno - even forgot about one student at the end of his day. This particular foreman (group leader) stayed there overnight and into the next day. It wasn’t until his wife called the factory and blasted Ohno for his forgetfulness that she finally got to see her husband. There is some interesting dynamic here that we would never see on this side of the world. Trying to get a superintendent, the equivalent to the group leader function at Toyota, to do this is near impossible. Try this for 10 minutes and the backlash is about to hit you. Regardless, there's a great story here.
During times of observation, something happens, and your mind wanders to the point where you are asking “who.” Who did this? Who are the guilty parties? This is not what they are supposed to be doing. Each time the master came back, you were expected to have a deeper analysis. You would address more issues and have thought more deeply about why. Notice that he did not ask you to find the guilty parties. He did not ask you to answer the five who’s. Often when you ask why, the first why is a person who made a mistake, but when you ask why that person made a mistake it usually will drive down to a system cause.
What should be happening is you are starting with a large problem that may be very vague or even symptoms of the problem (see below). Usually the master – Taiichi Ohno in this case – takes you right to where the problem originates. He has identified for you the point of origin of this problem. Then by asking the 5 Whys, yes, you can get to the root cause of that problem. What is missing is the narrowing down the symptom to the point of cause.
Ask the 5 Where’s – Where did this come from? Where are the instructions? Where is the answer detailed?
The point is to ask “where” five times until you get to the point of cause. We have quality problems. We want to solve these quality problems. There are many things that cause quality problems. We do not even know where to start. You need to more clearly focus your problem statement. Then you go beyond this to ask where the problem really originated. Then you can find the direct cause. Before you even start asking the 5 whys, you must identify the point of cause—where the problem originated- and the direct cause at that point in the process.
Figure 1 Narrowing the Focus (from the book Developing Lean Leaders at All Levels)
With our limited capacity as human beings lately, we are being challenged to meet the attention span of a goldfish. I’m even amazed that you have made it this far in the article. All joking aside, we do not practice disciplined problem solving. The word “disciplined” is the key word here. Having the discipline to ask the five where’s before the 5 whys. Understanding that without getting to the point of cause, you are doing absolutely NOTHING. You may actually be making the problem worse. What I learned early on as an engineer is that by eliminating the symptom, you have effectively eliminated the connection to the point of cause. It will come up again in the future, and this time it will result in a worse condition. Heaven forbid it affects safety.
Excerpt directly from the book: Developing Lean Leaders at All Levels
There is a famous Taiichi Ohno story where he told Nampachi Hayashi, one of his best students, to observe the assembly line until he saw a problem. Hayashi identified a serious quality problem and was all pumped up to start solving it. Then Ohno demanded, “Where did that problem occur?” The problem was a part that did not fit right, and when he thought about it, Hayashi realized it might have occurred in how the part was manufactured in an earlier stage. Ohno demanded to know why he was here if the problem was there.
Hayashi started running to the upstream process and Ohno stopped him in his tracks asking harshly where he was going. “Back to the manufacturing process where the problem probably originated to go and see,” Hayashi replied. Ohno then asked “What about the problem in assembling the part. Will you let bad assemblies be made?” He was pointing out that Hayashi must think deeply about the problem, but first must contain the problem in assembly before getting to the root cause in manufacturing. Ohno was not a fun guy to learn from, though extremely effective.
Learning from the Masters
I have been extremely privileged to learn from these stories and adopt the learning into my practices. How else can you become a productivity guru without understanding these basics? One of my other respected sources is Ritsuo Shingo, the son of Shigeo Shingo. One of Ritsuo’s favorite lessons is on source management. Basically meaning the same thing as written above. We must get to the source and change can happen. Dealing with what we think is a problem – later in the process – is devastatingly difficult and sucks the energy out of you. This above all things represents a type of waste in the life of a Lean practitioner. It encompasses the other wastes and is called a waste of life. You are wasting time, wasting your life, solving problems without asking the 5 Where’s first. Start asking 5 Where’s instead of the 5 Why’s. It seems kind of obvious to me that the 5 Why’s come naturally when you are focusing on the point of cause.