How To Solve Almost Any Problem With Toyota’s 5 Whys Approach?
The simplest solution is almost always the best. Toyota has taught us how to easily get to the bottom of the problems. Its “5 Whys” Root Cause Analysis Technique can help you not only in your software projects but in any other field as well.
--
5 Whys
The “5 Whys” was developed at Toyota as part of the Toyota Production System. The goal of this technique is not to settle for the first answer, but to ask more “Why” questions to get to the real root of the problem.
Let’s say there was an accident, a worker fell over and broke his arm. We can ask:
1. Why did he fall over? — Because the floor was wet
The first answer may seem satisfactory. The floor was wet and a worker fell over. The floor is now dry and the workers have been equipped with rubber boots. The 5 Why approach, however, teaches us not to stop at the simplest explanation and continue to ask Why questions.
2. Why the floor was wet? — Because the pipe under the ceiling is leaking
We just discovered that the problem could happen again. If the pipe is leaking, it must be repaired. This answer is much better than the previous one, but 5 Whys keeps us asking even more Why questions.
3. Why the pipe is leaking? — Because 6 months ago, the scheduled review did not take place
We just found out that the problem is more complex. The utilities (water, electrical, fire protection system) in the plant should be inspected as soon as possible. Before we complete our investigation, we should ask another Why.
4. Why the scheduled review did not take place? — Because the quality management system didn’t send a notification
The problem is getting serious. The audit plan should be verified as soon as possible, because the company may be at risk of losing its ISO certification. Before we fix that, we are left with one last Why.
5. Why was the notification not sent? — Someone hacked the server and changed the settings
We got to the root of the problem. Someone, perhaps a competitor, hacked a server that was available without a VPN. We must secure the server, assess whether and what other damages have been caused, and review the company’s security procedures.
Summary
The number 5 is arbitrary but is usually enough to determine the real cause of the problem. The solution can be successfully used not only in the production industry but also in any other field:
- Scrum Retrospective as a tool for finding the root cause of problems
- A tool for analyzing the market \ customer behavior and formulating hypotheses that can be verified experimentally
- Analysis of successes and failures in your professional and personal life
I have been using 5 Whys successfully for over 10 years. I would highly recommend this “stupid simple” method to anyone who is not satisfied with the first, shallow answers.
Try it out and observe the amazing results you can get with it.
