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5 Whys
Frank Voehl
CONTENTS
Definition
User
Often Used in the Following Phases of the Innovative Process
Tool Activity by Phase
How to Use the Tool
Advantages
Disadvantages
Example
Case Study
National Aeronautics and Space Administration O-Ring Failure
Evidence and Risk Assessment
Software
Suggested Additional Reading
DEFINITION
The 5 Whys is a technique to get to the root cause of the problem. It is the practice of asking five times or more why the failure has occurred in order to get to the root cause. Each time an answer is given, you ask why that particular condition occurred. As outlined in this chapter, it is recommended that the 5 Whys be used with risk assessment in order to strengthen the use of the tool for innovation and creativity-enhancing purposes.
USER
This tool can be used by individuals, but its best use is with a group of four to eight people. Cross-functional teams usually yield the best results from this activity.
OFTEN USED IN THE FOLLOWING PHASES OF THE INNOVATIVE PROCESS
The following are the seven phases of the innovative cycle. An X after the phase name indicates that the tool/methodology is used during that specific phase.
• Creation phase X
• Value proposition phase
• Financing phase
• Documentation phase
• Production phase X
• Sales/delivery phase X
• Performance analysis phase X
TOOL ACTIVITY BY PHASE
• Creation phase—During this phase, the 5 Whys technique is used to get to the root cause of questions like, “Why does the customer want that?”
• Production phase—During this phase, the 5 Whys is used to get to the root cause of questions related to problems that are defined and implementing the proposed initiative.
• Sales/delivery phase—During this phase, the 5 Whys tool is used to get to the root cause of problems like, “Why aren’t the customers buying this product?”
• Performance analysis phase—During this phase, the tool is used to answer questions like, “Why was the return on investment so low?” or “Why was this product so profitable?”
HOW TO USE THE TOOL
As previously mentioned, remember that the ease of using the 5 Whys method and the time required for its processing have to be balanced with the potential for the problem to recur if the 5 Whys does not work. In other words, one of the problems with using the 5 Whys is that it does not always uncover the root causes when the cause(s) is not known. This is why some type of risk assessment should always be used with the 5 Whys.
You should also remember that the 5 Whys method presumes that each symptom has one cause, and yet in many cases, this is not true. The result is that this type of analysis does not always show several related variables that are causing the symptom. Also, how well the 5 Whys works for innovation depends, to a degree, on the skill of the person using it. If one element of the 5 Whys has an incorrect answer, it can throw off the entire analysis. Lastly, this method is very often not easily repeatable. For example, having three people applying the 5 Whys can often come up with two or three different answers.
Three possible ways to strengthen the 5 Whys include
• Gather data and evidence to demonstrate why the answer to any of the 5 Whys is likely and plausible versus not likely.
• Couple data analysis with good risk assessment.
• Come up with a baseline with time frames of the particular events that detail how the problem happened or the opportunity unfolded.
When you gather evidence to support an answer to any of the 5 Whys, you are avoiding the trap of falling into a deductive thinking and reasoning mode to answer one of the 5 Whys. You should also add a test loop to every one of the Why levels that attempts to validate the answer through evidence. A risk assessment with your 5 Whys tool allows you to cut down on the weakness in the method in those cases where the true root cause is not found. Also, if the 5 Whys technique does produce a likely root cause, yet there is uncertainty regarding the true root cause, a risk assessment can be useful to see if a more stringent root cause analysis should be pursued in order to do a more stringent analysis.
The 5 Whys was originally adopted from Japanese management systems as a problem-solving tool and can be useful for solving hidden problems that in many cases prove to be symptoms of underlying hidden issues that often escape notice. While a quick fix is often adopted, in many problem situations, it may well be a poor, not very useful solution, and in the final analysis may not solve any or just part of the problem. To solve the problem with a complete solid outcome, you need to systematically do single-case boring down through the layers upon layers of symptoms to eventually reach the underlying cause. As originally developed by Sakichi Toyoda, the 5 Whys technique is a straightforward and powerful tool for systematically uncovering the root of a problem so that it can be dealt with effectively and prevent it from recurring over and over again.
As previously mentioned, Sakichi Toyoda was the first to develop the 5 Whys tool in the 1930s. As the founder of Toyota Industries, he was a respected businessman whose technique eventually became popular in the 1970s; Toyota, along with most of the world, still uses it to solve problems today. Toyota has a go and see philosophy. This means that its decision making is based on an in-depth understanding of the processes and conditions on the shop floor, rather than reflecting what someone in a boardroom thinks might be happening.
The 5 Whys technique is true to this tradition, and it is most effective when the answers come from people who have hands-on experience of the process being examined. It is remarkably simple: when a problem occurs, you uncover its nature and source by asking why no fewer than five times. The 5 Whys is a simple, practical tool that is very easy to use. When a problem arises, the suggestion is to keep asking the question why until you reach the underlying source of the problem, which sometimes requires more than one path to reach the root cause(s). In some cases, the term countermeasure is used to designate an action or combination of actions that seeks to prevent the problem from surfacing once again, while a solution just seeks to deal with the immediate problem situation. As such, the use of countermeasures is considered by many to be more robust, and more likely to prevent the problem from recurring.
Both individuals and groups can use the 5 Whys in the innovation/idea creation process (is this a good idea, and why?), and in troubleshooting (is this a significant or important issue?), quality improvement (are there quality issues that are surfaced?), and also in problem solving (is the root cause of the problem observable or detectable?). Many people find that it is best for simplistic or not-too-difficult opportunities. (Note: In many cases involving more complex or critical problems, the 5 Whys can lead you to pursue a single track of inquiry when there could be multiple causes. This is overcome by pursuing multiple paths, as the Case Study at the end of this chapter indicates.)
The simplicity of the 5 Whys tool gives it great flexibility, too, and it combines well with other methods and techniques; it is often a first choice before embarking on more complex tool usage. Each time you ask why, you need to look for an answer that is grounded in data and fact, as it should be an accounting of things that have actually happened and not speculation on events that might have happened. This approach focuses the 5 Whys on becoming just a process of deductive reasoning that can generate a number of possible causes and can sometimes create more confusion. Keep asking why until you feel confident that you have identified the root cause and can go no further. At this point, an appropriate countermeasure should become evident.
Advantages
• The 5 Whys technique is applied with relative ease, making it a simple-to-use practical tool for root cause analysis in problem solving.
• With frequent practice, it is possible to get to root causes in a relatively short period of time.
• Unlike more sophisticated innovation techniques, the 5 Whys methodology does not involve advanced statistical tools or sophisticated data segmentation.
• By repeatedly asking why four or five times, the essence of the problem and its associated solution become obvious.
• By repeatedly asking why multiple times, you can peel away in a systematic manner the various layers of symptoms, which then can lead you to identify the opportunities you are looking for, along with the root causes of a problem.
Disadvantages
• While many companies have successfully used this tool, the method has some inherent limitations, which include the inability to distinguish between causal factors and the root cause, and a lack of rigor where the user is not mandated to do sufficiency testing.
• Using 5 Whys does not always lead to root cause identification when the cause or the opportunity is unknown.
• If the cause is unknown to the person or group doing the innovation, using 5 Whys may not lead to any meaningful answers.
• An assumption underlying 5 Whys is that each pres...