Method 5 Why [Asking five time “Why?”] perhaps the simplest among the variety of ideas born by Toyota. But at the same time incredibly strong. And besides, it is very famous.
Currently, the technique of determining the root cause of a problem with a five-fold “Why” question is used in the concepts of lean manufacturing, Kaizen, 6 sigma and others. Moreover, the scope of application of this stunningly effective tool has long expands beyond production. In the manner characteristic of families in the process of analyzing problems. They dig into their true causes in various areas of human activity. And this is not surprising.
First, the method is easy and universal. Describing a thousand times in the literature and the Internet. Secondly, like any other idea from the category of “common sense” – it comes to mind regardless of knowledge of the history of production management. And it saves amazingly time – 10 minutes are enough for analysis.
Taiichi Ono, describing the system he created. Refers to this method as the scientific basis of Toyota’s Production System. In doing so, he refers us to Sakichi Toyoda. Whom he calls the author of the rule. It is assume that the idea of the method was formulating by him in the 30s of the twentieth century.
For the sake of justice, it should be noted that the question “Why?”. In the search for the root causes and their occurrence began to be used by philosophers of the IV-III centuries BC. e., And the author of the cause-and-effect concept using for any proof in logic, Socrates is considered. But in matters of increasing productivity and reducing costs. This method was first used in the Toyoda family.
Five “Why?”
The basis of Toyota’s scientific approach is to ask the question “Why?” five times. When a problem is detected. (Why), Which is denoted as 5W.
If you get answers to the question “Why?” five times, the cause of the problem. The method of solving it will become obvious.
The solution (or “How?” – how-to) is denoted as 1H.
Thus, five “Why?” equal to one “How?” (5W = 1H).
Real cause
Under the “cause” of the problem lies its root cause. In each case, we have to get to the bottom of the real cause by asking the question five times, “Why?”. Otherwise, countermeasures cannot be taken, and the problem truly resolve.
So, the Five “Why?” is an effective tool for both individual and collective study of the cause-and-effect relationships underlying a particular problem. Determining causal factors, and identifying underlying, root causes. The method is useful when the true cause of the problem is not clear. And there are not enough resources with details research and statistical analysis to solve it.
At the same time, it is important not to find someone to blame. As is customary in traditional management. When each problem has a face and a name, but to identify a systemic cause. “No accusations, no punishments” – as we know – is one of the key differences between Toyota’s system of thinking. The traditional management paradigm.
Solving even all intermediate problems, without paying attention to the root cause, will sooner or later lead to repeated failures. And punishing the “guilty” will not only forever close the possibility of their participation in the search for true factors but will also provoke their desire to hide any inconsistencies.
Why the Five “Why?”
The number 5 is most likely chosen empirically, but there is probably a certain sacrality. It so happened that five denotes completeness. Five questions are usually enough to identify the source of the problem. But despite the name, finding the causes of each specific discrepancy may require both fewer and more questions.
Since several options may arise when answering the question posed, the “5 why” method does not exclude the construction of a “tree” of reasons. Therefore, the approach is similar to the method of cause-and-effect diagrams and Ishikawa diagrams (“Fish Bone”). It is quite possible that some reasons in the process of analysis will be common to several branches at once.
The five “Why?” analysis follows one answer to the question “How” for each of the root causes of the resulting tree or diagram. And, of course, the answers received should result in the implementation of decisions.
In order for you to have a more complete understanding of the 5 “why?” method, I would like to use excerpts from the original source, and quote the architect of the Toyota production system, Taiichi Ono:
A five-fold “Why?”
Have you ever had to stop and ask yourself five times in a row, “Why did this happen?” Let’s try to do it together. Imagine, for example, that your car has stopped working:
1. Why did the car stop?
Because there was an overload, and the fuse flew.
2. Why was there an overload?
Because the bearing was poorly lubricated.
3. Why was the bearing poorly lubricated?
Because the pump supplying the lubricant was not working well.
4. Why did it not work well?
Because the piston was worn and loose.
5. Why did the piston wear out?
Because they didn’t put a filter in, and metal shavings got into the piston.
Five repetitions of the question “Why?” will help you understand the root cause of the problem and solve it.
Cycle of Questions!
If you do not go through the whole cycle of questions, then you may decide that it is enough just to replace the fuse or pump piston. Then, in just a few months, the same problem with the car will arise again.
Strictly speaking, Toyota’s production system is based on the use and development of this particular scientific approach.
Five times asking the same question “Why?” and each time we answer it, we can get to the bottom of the problem, which is often hidden behind more obvious, superficial reasons.
“Why at Toyota Motor Company one worker can drive only one loom, and at the Toyoda weaving factory, one young girl controls 40 or 50 automated looms at once?”
Starting with this question, we received the following answer: “The machines at Toyota are not designed to autonomously stop when a single processing cycle ends.” Hence the idea of autonomation of machines was born – their automation with elements of human intelligence.
To the next question:
“Why can’t we make sure that the parts are served exactly on time?”
The answer was: “Because the speed at which the parts are made does not allow us to know how many of them are produced per minute.” Hence the idea of equalizing production.
The first answer to the question,“Why do we produce too many parts?” was, “Because we can’t slow down or completely prevent overproduction.” Thus came the idea of visual control, which in turn led to the idea of kanban.
In the previous chapter, it was noted that Toyota’s production system is based on the complete elimination of losses. Why are there losses at all? Asking such a question, we actually come to the question of profit, which is the main condition for the normal functioning of the business. At the same time, we wonder why people work.
In the functioning of a manufacturing enterprise, data plays a very important role, but I believe that the real facts are more important. If, in the event of a problem, we do not persistently search for the root cause, the measures taken may be in vain. That’s why we keep repeating the “Why?” question. This is the scientific basis of the Toyota system.
Toyota & 5 Why
When faced with any problem, I always ask the question “Why?” five times. This rule is also learned from Toyoda Sakichi, who had a habit of observing. You can talk as much as you like about improving the work, but specific proposals will arise only after a thorough study of production. Spend the whole day in the production department and observe what is happening. In the end, you will understand what needs to be done.
Whether it’s an issue, an opportunity, or both, Toyota spends the time and effort to do the homework needed to see the big picture and go beyond the obvious, which will allow you to distinguish the underlying causes and signals from the symptoms when making a decision. Therefore, Toyota focuses on the fact that it is always necessary to go and see everything with your own eyes, and then 5 times ask yourself the question “why”.
Production System of Toyota
Being able to see everything with their own eyes helps managers understand how challenges and/or opportunities manifest themselves. However, homework will not be considered complete until, as I said before, Toyota managers ask themselves the question “why” 5 times to understand the main causes of the problem or the main ways to realize the opportunity.
As Taiichi Ono, the creator of the Toyota production system, explained: “To tell the truth, the Toyota production system is built on the practice and development of this scientific approach. If we ask ourselves “why” 5 times and each time we give an answer to this question, we will be able to understand the real cause of the problem, which is often hidden behind more noticeable symptoms. ”
Deep Breath !
There is a puddle of oil on the floor of the factory floor. Why? Oil leaks out of the machine. Why? The gasket is damaged. Why? Because we bought gaskets made of cheap material. Why? Because we were given the best price for them. Why? Because the work of purchasing agents is rewarded and evaluated based on short-term savings, not long-term results.
So, what is really the problem and, accordingly, what conditions should the solution meet? In a puddle of oil on the floor that can be easily wiped off in less than two minutes and no one from the management will notice it? Or is it a procurement agent reward system that leads to the purchase of imperfect equipment and therefore needs to be changed? Having the oil wiped off the floor will solve superficial issues, but will not prevent the problem from recurring, while the new procurement rules will.
I really hope that in your practice you use this simple technique, and if not, that this material will encourage you to use it in your work and not only.