The 5 Whys

Recently, while researching another topic for another blog post, I came across the concept of the 5 Whys. Essentially, this is a technique that is extremely useful in identifying the root cause of a problem and not one of its symptoms.

How Does It Work?

This technique was created by by Sakichi Toyoda, who implemented it in his company, Toyota, to improve & optimize various processes. The process is extremely simple as all it involves is asking the simple question "Why?" five times in order to get to the root cause of a problem. Now you don't always have to ask it five times to get to the root cause, but this is just the average number of times it takes. Sometimes it may take only three repetitions, whereas another time it may taken seven times. It all depends on the problem.

If we look at the following as a simple example, you will see how it works:

Problem - We have a lot of defects being continuously logged for our provisioning system

  1. Why? - We have no unit tests for the system
  2. Why? - We never had time to write them
  3. Why? - We have a lot of feature creep from the product owners
  4. Why? - There are no processes in place to prevent this

In the example above, if you didn't dig down a deeper to find the actual cause of the problem you would more than likely have tried to correct a symptom.

For example, if the team said that the quality was poor due to there not being enough unit tests, their solution to this would be to write more tests. However, more than likely, that would have failed as the underlying problem still exists that the team doesn't have enough time to actually write them. Now, if the team scheduled more time for unit tests to be written, they would more than likely fail again, as there is another underlying problem, feature creep. This process would probably be repeated until until the root cause is finally identified, which may take a while. The 5 Whys approach would get you to solving the actual issue much faster.

How Many Whys?

Now you may be wondering to yourself "How do you know when you have reached the root cause?" A rule of thumb is that the real root cause is often a process that is missing or not being followed. One key thing to remember, that many leaders fail to acknowledge, is that people don't fail, processes do.

It is also important to note that there may be multiple root causes, so in those cases drawing it out in a graph, or chart format, may help quite a bit in identifying them all.

The Last Why

As you can see the 5 Whys strategy is an effective way to quickly get to the root of a problem. You can use it to improve the quality of processes, for troubleshooting & solving a myriad of problems. Personally, I have found it extremely useful in retrospectives to find the actual cause of a problem, so that actions can be taken in order to improve the process.

Just remember, this isn't a silver bullet and some complex situations may require a more sophisticated approach, but for the broad range of issues, it works quite while.

Until next time...keep asking why ;)

Mauro Da Silva

Learning everyday about software development, leadership & self improvement

South Africa