What is the problem or symptom you are facing?
Examples:
  • Our profit has been declining for 6 months
  • The throughput on my production line has dropped 10%
  • I'm spending too much time on social media
  • My site has no organic traffic

About 5 Why

The problem solving technique for better root cause analysis

When confronted with a problem, we are often too quick to jump to solutions that do not address the underlying root cause. This leads us to a short-term fix that acts as a bandage, not a robust solution. To find long-term solutions to any problem we have to make sure they address the root cause, not a symptom of the problem or the top-level issues. In some cases this is obvious - if a car won't start, the first action should not be to fill it up with fuel. Instead, we check to see if the fuel tank is empty, if the battery is charged, etc. This sounds trivial, but too often we jump to a solution based symptoms before we have proplerly addressed what is causing the symptoms. These "solutions" may look right at first, but since they are just a bandage for the symptom, the problem will happen again and likely become recurring.

How Five Why helps

When we utilize the five why technique, we continue asking and answering "why" until we can't anymore. We drill down as far as possible before stopping to look for solutions. These solutions are referred to as "countermeasures" because they should directly counter the root cause. The book Toyota Production System has the classic example of this as shown below.

Problem: a factory machine has stopped working
  1. Why did the machine stop?
    A: there was an overload that blew the fuse.
  2. Why was there an overload?
    A: a bearing was not lubricated correctly.
  3. Why was it not lubricated correctly?
    A: the lubrication pump was not pumping lubricant fast enough.
  4. Why was the pump not pumping sufficiently?
    A: the pump shaft was worn out.
  5. Why was the pump shaft worn out?
    A: there was no filter and metal scraps got in and worse the shaft down.
Root cause: in this case, the underlying reason the machine stopped working is there was no filter.

Go farther than 5 when needed

As you can see, the number 5 is not the point; in this example, we could have seperated the last why and asked "why did scraps get in" first, then found the underlying cause. And although we don't know the original story, it is likely we could continue on farther than this. For example, "why was the filter missing?". Was that someone not following the correct process? Or a process that was not sufficient to make certain filters were replaced?

Don't simply replace the fuse

In the example above, simply replacing the fuse or lubricating the bearing would have got the machine running again. But in a few hours or days the issue would have happened again. Neither replacing the fuse or lubricating the bearing address the root cause; they are not true countermeasures. They are short-term bandages that appear to solve the problem but in reality they only address symptoms.

Five Why templates and examples in multiple formats you can customize

Learn more about Five Why

Five Why came out of Toyota Production Systems (TPS) and is often utilized at companies who have a lean culture. These books will help you learn more about TPS and lean. If you buy one of them, I may get affiliate commissions, but that did not impact what was placed on this list; these are helpful books regardless of whether you use this link or find them elsewhere.