The 5 Whys Technique: Discover the Root of a Problem for Kaizen
If you are going to do kaizen continuously…you’ve got to assume that things are a mess. Too many people just assume that things are all right the way they are. Aren’t you guys convinced that the way you’re doing things is the right way? That’s no way to get anything done. Kaizen is about changing the way things are. If you assume that things are all right the way they are, you can’t do kaizen. So change something!
– Taiichi Ohno
INTRO
When problems arise over and over, it’s often a sign of deeper issues at play. Often times a quick fix is applied to a problem, but doesn’t get to the root cause of what is really going on so that you can deal with it once and for all.
The Five Whys, originally developed by Sakichi Toyoda and later included in the Toyota Production System, also happens to be the framework most commonly used by inquisitive children. It is based on the concept of kaizen, the Japanese word meaning “change for better” or “improvement.”
OBJECTIVES
- The goal of the technique is to determine the root cause of a problem by repeating the question. Each answer forms the basis of the next question. The key is to avoid cognitive bias and instead, trace chains of causality.
RESOURCE LINKS
You can use 5 Whys for troubleshooting, quality improvement, and problem-solving, but it is most effective when used to resolve simple or moderately difficult problems. Follow the steps below.
Watch the below video for an example of The 5 Whys Problem-Solving Method.
STEP 1: Assemble a Team
Gather a group of people familiar with the problem you are trying to solve, and include someone to act as a facilitator to keep the team focused.
STEP 2: Define the Problem
Discuss the problem as a team, and write a brief, clear problem statement. Write this statement on a whiteboard or shared Google Doc leaving enough space to add your answers to the repeated “Why?”.
STEP 3: Ask the First “Why?”
Search for answers grounded in fact, not simply guessing at what might have happened. This avoids the process generating large number of possible causes. However, you may have a few answers, and that is fine. Record the answer(s) as succinct phrases, rather than single words.
STEP 4: Ask “Why?” Four More Times
For each of the answers from Step 4, ask four further “whys” in succession. Each time, frame the question in response to the answer you’ve just recorded.
STEP 5: Know When to Stop
You’ll know that you’ve revealed the root cause of the problem when asking “why” produces no more useful responses, and you can go no further. Review Tip 3 below for additional insight.
STEP 6: Address the Root Cause(s)
Now that you’ve identified at least one root cause, you need to discuss and agree on the counter-measures that will prevent the problem from recurring.
TIPS
- The 5 Whys uses “counter-measures,” rather than “solutions.” A counter-measure is an action or set of actions that seeks to prevent the problem from arising again, while a solution may just seek to deal with the symptom. As such, counter-measures are more robust, and will more likely prevent the problem from recurring.
- Try to move quickly from one question to the next, so that you have the full picture before you jump to any conclusions.
- The “5” in 5 Whys is just a rule of thumb. In some cases, you may need to ask a few more times before you get to the root of the problem.
- In other cases, you may reach this point before you ask your fifth “Why?” If you do, make sure that you haven’t stopped too soon, and that you’re not simply accepting “knee-jerk” responses.
- The important point is to stop asking “Why?” when you stop producing useful responses.
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