Get to the root cause by “Asking Why?” five times.
We have all heard it, read it. Our sensei’s have pounded it into us. It is a cliché, obviously, since getting to the root cause of a problem is (most of the time) a touch more complicated than just repeatedly asking “Why?”
Maybe not. Maybe it is a matter of skill.
Some people are really good at it. They seem to instinctively get to the core issue, and they are usually right. Others take the “Problem Solving” class and still seem to struggle. So what is it that the “naturals” do unconsciously?
Let me introduce another piece of data here. “Problem Solving” is taught to be an application of the scientific method. The scientific method, in turn, is hypothesis testing. How does that relate to “ask why? five times” ?
Each iteration of asking “why?” is an iteration of hypothesis testing.
How do you “ask why?”
Observe and gather information.
Formulate possible hypotheses.
For each reasonable possibility, determine what information would confirm or refute it. (Devise experiments, which really means “Decide what questions to ask next and figure out a way to answer them.”)
Observe, gather information, experiment. Get answers to those questions.
Confirm or refute possible causes.
At each level, a confirmed cause is the result of “observe and gather information” so the process iterates back to the top.
Eventually, though, a point is reached where going further either obviously makes no sense, or is of no additional help. If you are now looking at something you can fix, you are at the “root cause” for the purpose of the exercise. Yes, you can probably keep going, but part of this is knowing how far is far enough.
Is this something I can fix easily?
Does it make sense to go further?
Otherwise, iterate again.
Now: Devise a countermeasure.
A countermeasure, itself, is a hypothesis. You are saying “If I take this action, I should get this result” i.e. the problem goes away.
Put the countermeasure into place. Does it work? That is yet another experiment only now you are (hopefully) confirming or refuting your fix on every production cycle. The andon will tell you if you are right.
We tell people “Ask why five times” but we really don’t teach them how to “ask why.”
The book examples usually show this neat chain of cause/effect/cause/effect, but the real world isn’t that tidy. When the problem is first being investigated, each level often has many possibilities. Once the chain is built then the chain can be used as a check.
But that isn’t how you GET there.
Why don’t the books do a good job teaching this?
“They” say that critical thinking is difficult to teach. I disagree. If the people who do it unconsciously can step back and become consciously competent, and know how they do it, then it breaks down into a skill, and a skill can be taught.
A Real World Example
My computer works, but it’s network connection to the outside world doesn’t.
OK. What could be wrong?
It could be software in the computer.
It could be a problem with the hardware.
Look at where the cable plugs into the back of the computer. Are the little lights flashing? No? Then there is no data going through that connection.
How could that be?
Well.. the it could be a problem in the computer or operating system.
It could be a problem with the hardware in the computer.
It could be a bad cable.
It could be a problem behind the network jack on the wall.
The QUICKEST thing to do is unplug the cable and plug my co-worker’s cable into the computer. (Please make sure he isn’t busy with email before you do this!). Do the lights come on? Yes? Does your network stuff work now? Yes? Then it isn’t anything in the computer. You have just done a hypothesis test – conducted an experiment.
Take his KNOWN GOOD cable out of the wall and plug it into your jack. Does your network work now? Yes? You have a bad cable. No? It is a problem behind the jack.. call I.T. and tell them. (unless you are at home, then head to the little blue box in the basement and start looking at flashing lights down there. But same process.. as you systematically eliminate internal causes, you are left with an external one.)
This is a natural flow, but most people wouldn’t describe it as “asking why?” or “hypothesis testing” – and the big words scare them off.
Still – when you (the lean guru) are teaching others, it is important for them to understand HOW TO ASK WHY is just a process of learning by systematic elimination of the impossible. (Whatever remains, however unlikely, must be the truth – Author Conan Doyle through Sherlock Holmes)