Root Cause

For want of a nail a shoe was lost. For want of the shoe, a horse was lost. For want of the horse, a knight was lost. For want of the knight, a battle was lost. For want of the battle, a kingdom was lost, and all for want of a nail.

This proverb, which dates back to at least the 14th Century, exemplifies the foremost challenge of design, that is, developing a deep understanding of problems.

The temptation, in fact the human tendency, is to presume that problems have single, proximal causes, the cause immediately preceding the problem. The kingdom was lost because the battle was lost, and that's it. That is how news is typically reported, how history is typically written, and how courses are typically taught, but this is rarely the case in reality.

The kingdom was lost due to a paucity of nails. That is the deeper truth in the proverb, the root cause.

But, of course, even this is over simple. Was there a shortage of iron that led to the shortage of nails? Perhaps the shortage was due to bad inventory management, or perhaps, an incompetent apprentice. All of these factors and more could have played a part in the loss of the kingdom.

So, the challenge is to understand the causal chain that led to the observed problem, identify the key links in that chain and how they relate to one another, and then target those areas where we have the most leverage to make a significant impact.

The goal of this lecture is to give you a tool to figure out how to ask the right question, to understand problems deeply. That tool is called Root Cause Analysis.

Root Cause Analysis is a way of understanding problems in terms of their causes, with the goal of finding the first event that caused everything else. The notion is that everything after the root cause is a symptom or an aftereffect, and treating symptoms won't cure the disease.

So, what is a root cause? A root cause is defined as the key initiating cause in a sequence of events that leads to a problem event.

Most problems, especially difficult problems, have multiple causes, and their proximal causes are rarely their root causes.

Now, there are a bunch of different ways to do root cause analysis. We're going to focus on a technique called "The Five Whys," that is, asking why an event occurred, five causes deep, plus or minus. This technique was developed in the 1930's by Sakichi Toyoda, the acclaimed inventor and founder of Toyota Industries Corporation, which would later become Toyota Motor Corporation. The Five Whys remains a key part of problem solving training for Toyota employees to this day, not to mention designers, engineers and managers throughout the world.

An example of how it works. Why did the welder burn herself? She wasn't wearing protective clothing. Why wasn't she wearing protective clothing? It was hot in the room. Why was it so hot? The air conditioner was broken.

The root cause of the accident was a broken air conditioner. This is not to say that you don't address other problems in a causal chain. For example, perhaps the welder needed better safety training. But, you focus on the root cause, fixing the broken air conditioner.

One more example. During a visit to one of Amazon's Fulfillment Centers in 2004, Amazon CEO Jeff Bezos learned about an accident in which a worker injured his finger. He reportedly walked to the whiteboard and started asking the group questions in the manner of Five Whys.

Why did the worker damage his thumb? The team replied, "because his thumb got caught in the conveyor." Why did his thumb get caught in the conveyor? The team said, "because he was chasing his bag, which was on a running conveyor." Why did he chase his bag? The team said, "because he had placed his bag on the conveyor, which then started unexpectedly." Why was his bag on the conveyor? The team replied, "because he was using the conveyor as a table." Ah ha. Bezos and team concluded that the root cause of the accident was really the lack of a surface on which associates could lay their belongings.

The solution was to add tables to the work stations, which is what they did.

So, whether you use your understanding of root causes and the Five Whys technique to identify and solve the right problem, or to more deeply understand problems and identify the causal links where you have the most leverage, remember the kingdom was lost for want of a nail.

"...all for want of a nail."

"The kingdom was lost due to a paucity of nails."

"So, the challenge is to understand the causal chain that led to the observed problem."

"A root cause is defined as the key initiating cause in a sequence of events that leads to a problem event."

"Most problems, especially difficult problems, have multiple causes, and their proximal causes are rarely their root causes."

Rules of performing 5 Whys

1. Write down the problem and make sure that all people understand it.
2. Distinguish causes from symptoms.
3. Pay attention to the logic of cause-and-effect relationship.
4. Try to make your answers precise.
5. Look for the cause step by step. Don't jump to conclusions.
6. Base your statements on facts and knowledge.
7. Assess the process, not people.
8. Never leave "human error", "worker's inattention", "blame John", etc. as the root cause.
9. Foster an atmosphere of trust and sincerity.
10. When you form the answer to the question "Why?" it should be from the customer's point of view.

Edited from Source: Wikipedia (https://en.wikipedia.org/wiki/5_Whys)

Define the Problem Correctly

by Todd Dewett

For any decision bigger than, hey, where are we going to lunch, the very first step in the decision-making process is correctly defining the problem. You have to consciously ask yourself, what's the real issue here? Your goal is to find the root cause. But far too often we're busy and stressed out. And we attack a problem without being as thoughtful as we should be. Without addressing the root cause you're really only dealing with the symptoms of the problem. Of course, that means you're not really solving the issue. And it will persist as a problem. To find the root cause sometimes it's helpful to ask the question, why, several times. Let me give you an example. Let's say you have an employee whose performance is off. You've noticed that his work has been late several times in the past month. But in the past that has never been an issue. There are several common reactions to the scenario. You might fire off an email or two to ensure the employee understands that you're concerned. Or maybe you stop by and tell them to get focused and meet their deadlines. After a few actions like these you might even formally write them up and add the reprimand to their personal file. But these are not the best reactions. You see, it's very likely that the work being late is not the problem, it's just a symptom. So inside your mind start asking why, why is the work late? Is the employee somehow unsuited for the task? Did the nature of the work change? Are there resource issues? Maybe there's some form of conflict you're unaware of that explains the situation, who knows? After thinking it through it's time to talk to the employee. Do it in private to show respect. Be clear and to the point. Ask about the problem, and don't assume you know the answer. You have to make the person comfortable enough to answer honestly so you can understand what's going on. For example, maybe they confide in you that they're ill. Or maybe they're distracted since they're caring for a family member. Or maybe they're just bored with their role. Who knows, there are many possibilities. Your goal is to discover the root cause because you can't help until you do. It is true that in high performing teams performance issues are often ironed out internally by the team without you intervening. But many times it's you who has to step in and help someone return to being productive. Your odds of doing that successfully go up significantly when you start by defining the problem correctly. You can start right now. Just think of your most persistent recurring problem. Then, start asking, why? With a little persistence you'll find the root cause. And then you have a real shot at solving the problem.

"You have to consciously ask yourself, what's the real issue here? Your goal is to find the root cause."

"Without addressing the root cause you're really only dealing with the symptoms of the problem."

What's Causing the Problem?

by Chris Croft

The absolute first step of problem solving and the one that often gets missed out is to be sure you've got the right cause. Facing the wrong root cause won't help. For example, replacing the wrong part, or even replacing the wrong person. This happens all the time. For example, many people think that if they could get a pay rise they would enjoy their work more and be happy in their life. But money might not be the cause of their unhappiness or their lack of enjoyment of their job. Or if you're not sleeping well, is the cause the fact that your bed isn't comfortable enough or the room isn't dark enough, or there's noise, or is it stress inside your head? If it's stress, then a new bed won't help. Sometimes we don't know the cause, so we resort to living with the problem instead. In factories, this would mean using inspection to just throw away the bad ones, which is wasteful, and also, a few bad ones will still always get through. In one factory where I worked we made very thin plastic sheets and the machine had about 100 settings. There were loads of rollers with temperature and pressure and speed settings and when the machine was working badly, we just fiddled with everything, hoping to get the combination right. It was only after months of experimenting that we found that the cause was one roller. It had to be running at just the right speed. So, we put a very accurate speed controller on that one roller. It was finding the cause that was the key. Sometimes there are two causes and we only know about one of them, so the problem continues, even after we think we've fixed it. An example of this would be your computer running slowly and maybe there are a number of unwanted programs running on it. Finding just one won't be enough. Sometimes one cause may have two or more effects and we only see the effects, so we start to assume that one effect is causing the other. For example, in hot weather, more people go swimming in the sea, and some get into difficulties and even drown, which is clearly a problem that needs solving. But also in hot weather, more people eat ice cream, and if you were monitoring these two things, you'd notice a correlation between ice cream consumption and drowning, and you might start thinking about banning ice cream. But, in fact, if you banned ice cream it wouldn't solve the problem at all, because you haven't got to the root cause, which is the hot weather. So, step one is to work out the cause and tackle that. You have to make sure it's the real cause. And the best way to do that is to compare control groups. Is there a difference in the swimming accidents between people who've eaten ice cream and those who haven't? If all of the people who get into difficulties have recently been eating ice cream, then it may indeed be the cause unless everyone on the beach has eaten ice cream. Comparing the proportions of ice cream eating on the beach and in the swimmers who get into difficulties, that's the way to prove it's the real cause. And if it's not, then you have to keep looking for what might be. So, the first part of the process is to get a list of possible causes, everything that's different about the ones who have a problem, and then work out which one or ones are the real cause. Then you can work on fixing that problem. So, for the problem you have in mind, what's the root cause? Are you sure there aren't any other causes as well?

Asking the Five Whys

by Chris Croft

Sometimes the cause of a problem might have an even deeper cause, and it's necessary to track them right down to the root. For doing this, there's a great technique known as the Five Whys. The idea is that you ask why maybe up to five times, certainly more than once, until you get right down to the start of the problem. For example, the phone number is wrong in the internal directory. Phone number wrong. You could just put it right, but first, why is it wrong? Because Fred typed it in there wrong. Why did Fred type it wrong? Because Fred was a temporary intern who maybe didn't care or perhaps wasn't trained. Why was someone like Fred doing this job? Why wasn't Fred trained? Why didn't someone check what Fred was doing? Because there isn't a proper quality system for looking after interns. No quality system. Why isn't there a quality system? You could see how asking why a few times begins to uncover a whole lot of problems in the system. In fact, sometimes the Five Whys aren't just a chain, they can be more of a tree. Sometimes there are several underlying causes. For example, why was the delivery late? Well, it could have been that we were short of staff, maybe a machine broke down, or perhaps we had a last minute quality problem. You then need to find out why these three things happened? And, again, shortage of staff could have a number of causes. So you end up with a tree of causes, and they all need to be sorted. And sometimes the Five Whys can go around in a circle. For example, why are we running out of fish in the Atlantic? It's because fishermen are using nets with smaller mesh and are catching all the small fish before they can grow into big ones. Small nets. But why is that? It's because there are no big ones left; they have to catch the smaller ones. But why are there no big fish left? It's because all the small ones are being caught. Hang on a minute, we've just been there. So what's happening is that the small nets are causing there to be no big ones left, and that means we have to have smaller and smaller nets. So, in this case we have to break the loop and stop the use of smaller nets, which isn't going to be easy. But usually, the Five Whys in an organization ends up pointing to one place, and that's management. For example, quality problems are caused by lack of training or processes, which are caused by lack of attention from management. Or a bad boss is caused by a system that encourages bad behavior, maybe politics or bullying, and the cause of the system being like that is lack of measurement of real results or lack of alignment of objectives between departments or lack of training or lack of monitoring of staff morale. And these are all management problems. Poor old management. In the end, everything is management's fault. And of course the result of this is that it's not necessarily in management's interest to ask why too many times. Although, a good manager would still do this. A bad manager would often just rather fix the surface problem, rather than dig deeper and find something big and expensive and possibly their fault. But to solve a problem you must get to the root cause or it'll keep cropping up. So, I'd like you to ask why at least two or three times for the problem that you have in mind at the moment, and maybe draw it out as a tree as you find more than one possible underlying cause. And keep digging deeper until you feel that you've got to the real root of it.