5 Whys

Quickly Getting to the Root of a Problem

The 5 Whys is a simple problem-solving technique that helps you to get to the root of a problem quickly. Made popular in the 1970s by the Toyota Production System, the 5 Whys strategy involves looking at any problem and asking: "Why?" and "What caused this problem?"
Very often, the answer to the first "why" will prompt another "why" and the answer to the second "why" will prompt another and so on; hence the name the 5 Whys strategy.
Benefits of the 5 Whys include:
It helps you to quickly determine the root cause of a problem.

Reference: Mindtools.com
It's simple, and easy to learn and apply.
How to Use the Tool:
When you're looking to solve a problem, start at the end result and work backward (toward the root cause), continually asking: "Why?" You’ll need to repeat this over and over until the root cause of the problem becomes apparent.

Note:
The 5 Whys technique is a simple technique that can help you quickly get to the root of a problem. But that is all it is, and the more complex things get, the more likely it is to lead you down a false trail. If it doesn't quickly give you an answer that's obviously right, then you may need to use a more sophisticated problem solving technique such as Root Cause Analysis or Cause and Effect Analysis.

Example:
In this example, the problem is that your client, Hinson Corp., is unhappy. Using the 5 Whys, you go through the following steps to get to the cause of the problem:
Why is our client, Hinson Corp., unhappy? Because we didn't deliver our services when we said we would.
Why were we unable to meet the agreed-upon timeline or schedule for delivery? The job took much longer than we thought it would.
Why did it take so much longer? Because we underestimated the complexity of the job.
Why did we underestimate the complexity of the job? Because we made a quick estimate of the time needed to complete it, and didn't list the individual stages needed to complete the project.
Why didn't we do this? Because we were running behind on other projects. We clearly need to review our time estimation and specification procedures.

Key Points:
The 5 Whys strategy is an easy and often-effective tool for uncovering the root of a problem. Because it's simple, you can adapt it quickly and apply it to almost any problem.
Bear in mind, however, that if it doesn't prompt an intuitive answer, you may need to apply other problem-solving techniques.