iSixSigma

5 Whys

Definition of 5 Whys:

As a child, you were always asking your parents “Why this?” “Why that?” “Why can’t I do this?” “Why can’t I do that?” Little did you know that you were preparing yourself to be a problem-solver looking for root causes when you would grow up. 

This article will discuss what is the 5 Why method of looking for a problem’s root cause, how to correctly ask the questions, and what benefits and best practices there might be to help you do a better job of improving your processes. 

Overview: What are the 5 Whys? 

The 5 Whys technique was developed in the 1930s by Sakichi Toyoda, the Japanese industrialist, inventor, and founder of Toyota Industries. The 5 Whys technique is an iterative, team-driven process that interrogates the problem by asking Why(?) a number of times, usually 5, thus driving the search to uncover the root cause of a problem.

Rather than using the phrase “solutions” once the root cause is found, the 5 Whys uses the term “countermeasures.” A countermeasure is action-oriented and seeks to prevent the problem from happening again, whereas a solution may just seek to deal with the symptoms.

Here is the 5 Why technique in a nutshell:

First, you must have a defined problem. Put together a team to address the problem. Then:

  1. List: Using a white board, flip chart, butcher paper, or other visual display, list five potential reasons for your problem.
  2. Evaluate: Using data, subject matter experts, or experience, evaluate each of the five potential reasons.
  3. Select: Select the one reason that seems to be the most likely potential cause.  
  4. List again: Now list five potential reasons for the potential cause that you selected.
  5. Evaluate again: Evaluate those five new potential reasons.
  6. Select again: Again, select the one reason that seems to have the most potential as a root cause.

Repeat the process of list, evaluate, and select as many times as needed until you feel that the root cause has been uncovered. The 

Unfortunately, many organizations don’t do the 5 Whys the correct way. Often, they:

  1. Look at the problem
  2. Offer one potential cause
  3. Ask “Why?” for that one cause
  4. And continue one at a time 

In the end, you will have only explored five potential causes. Doing it with the list, evaluate, and select approach, you will have assessed 25 potential causes by listing five for each iteration.

3 benefits of the 5 Whys 

This technique has been around since the 1930s. It has been shown to work and can be successfully applied to many situations. 

1. It is a simple yet powerful tool

With just the use of a flip chart and a few markers, a group of people can usually get to the root cause of a problem relatively quickly. 

2. Asking “why” 5 times focuses the team on getting to the root cause

Using this approach in a disciplined fashion will get you to focus on the causes and prevent you from jumping to conclusions as to the solution. 

3. Helps engage the people who deal with the problem  

Getting input from the people who deal with the problem and making them part of the solution can result in better buy-in and engagement. 

Why are the 5 Whys important to understand? 

While the 5 Why technique is simple, you must understand the proper mechanics of the method so that you get the best results possible.

It encourages collaborative problem-solving

Getting the team to collaboratively work together is not only important for the 5 Why problem solving session but for any future activities that would improve the process.

You want to focus on improvement, not blame 

Do not allow such causes as “human error,” “employee attitude,” “communication,” and other generic and ill-defined reasons to be used as the root cause. 

Understand the importance of having support from leadership 

Hopefully, in the end, the team will come up with a number of countermeasures that will remove the root cause(s) of a problem. It will usually fall upon leadership to provide the resources to make the change. Avoid future frustration by having management on board with this technique from the beginning. 

An example of the 5 Whys in use 

An example is in order.

You are on your way home from work, and your car stops:

  • Why did your car stop? Because it ran out of gas.
  • Why did it run out of gas? Because I didn’t buy any gas on my way to work.
  • Why didn’t you buy any gas this morning? Because I didn’t have any money.
  • Why didn’t you have any money? Because I lost it all last night in a poker game.

This example should illustrate the importance of digging down beneath the most proximate cause of the problem. Failure to determine the root cause assures that you will be treating the symptoms of the problem instead of its cause, in which case, the disease will return — that is, you will continue to have the same problems over and over again.

Also note that the actual numbers of whys is not important as long as you get to the root cause. One might also ask, “Why did you lose all your money in the poker game last night?”

Here’s another example. The Washington Monument was disintegrating:

  • Why? Use of harsh chemicals
  • Why? To clean pigeon poop
  • Why so many pigeons? They eat spiders and there are a lot of spiders at monument
  • Why so many spiders? They eat gnats and lots of gnats at monument
  • Why so many gnats? They are attracted to the light at dusk.

Countermeasure: Turn on the lights at a later time.

3 best practices when thinking about the 5 Whys 

Doing the 5 Whys is simple, but not easy. Keep the team on task and take advantage of the team members’ knowledge, experience, and enthusiasm.

1. Don’t try to do this alone; use a group of people involved in the process 

Five heads are better than one. Select a diverse group of team members to get the widest perspective. 

2. Focus on counter measures rather than solutions 

The solution to a headache is to take two aspirin. The countermeasure to a headache is to find out what is causing it and remove it. 

3. Be open and respectful of everyone’s input and participation 

Everyone’s idea has value. You never know who might hold the hidden gem. Listen and be respectful so people will feel comfortable offering their ideas — you’ll also have better buy-in once you find the root cause. 

Frequently Asked Questions (FAQ) about the 5 Whys

1. Can I ask more than 5 Whys? 

Yes. You can ask more than five or less than five. The key is, how many questions does it take to get to what appears to be the root cause.

2.  Can I use the computer to do the 5 Why exercise? 

It’s recommended that you use something more tactile like flip charts. This way, you can tear them off and hang them on the wall for everyone to see. The more visual you make the work, the better.

3. Should my manager run the 5 Why session or someone else?

Since the manager often has a stake in the outcome of the process, it might be best to use a neutral facilitator who can help keep the team on task, ask the right questions, and not get defensive when the potential causes are mentioned.

The 5 Whys wrapped up

The 5 Whys is an iterative, team-based approach to asking questions about the potential causes of a problem. Once the problem is defined, the potential causes should be listed, evaluated, and selected, and then repeated as many times as necessary to get to the root cause. 

Once the root cause(s) is identified, the team should recommend specific, action-oriented countermeasures to mitigate or eliminate the root cause of the problem. Remember, don’t just address the symptoms; you must find the underlying cause, otherwise the problem will resurface sometime in the future.

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