How many "Why's" should I ask?
Tracey Richardson??
??Retired from Teaching Lean Inc and Toyota | Author of The Toyota Engagement Equation?? Sharer of Collective wisdom the past 36 yrs
“Does it always have to be 5 Whys?†is one of the most frequent questions raised in my training classes. The answer is no. As with most lean tools, it’s important to understand the real purpose of this exercise. In this case, the “5 Why†label is meant to encourage you to ask why more than once or twice, in order to dig below the surface where the symptoms lie, and find the true root cause. The actual number of times you ask why is not critical: I have several examples where 2 why’s works best, and others where you might keep going until you’ve asked the question nine times.
To practice this method you must go to the gemba to determine the actual cause and effect relationship of what is happening, engaging and involving those affected by the issue in the process. Conducting your investigation from behind a desk or in a conference room will often lead to fighting over symptoms not root causes. This approach will invariably be driven by theories and opinions rather than facts, facts, facts. Avoid the temptation to rely on pre-conceived notions since they often take less time to investigate. Whenever I hear that time is an issue, I reflect on a quote by the late John Wooden: “If you don’t have the time to do it right the first time, when will you have time to do it over?â€
The important issue with this process is not to go too far. Continuing to ask why after you have located the root cause will change the context of the problem, or the scope of control you may have in forming appropriate countermeasures. You want to make sure that your countermeasure effectively addresses the root cause, and all the symptoms up the chain. You want to reach the level at which making a change will effectively and permanently address the symptom that prompted this exercise. (By the way, clearly seeing the chain of events helps you focus on seeing how the root cause of the problem is tied to one of three categories—lack of Standard, lack of following Standard, or wrong Standard—as opposed to being the “fault†of individual people.)
Consider the following example (have fun with it):
Problem: I was late for work.
Why? I was unable to get there on time.
Why? I overslept.
Why? My alarm clock didn’t go off.
Why? The clocking wasn’t operating as it normally does, in this case flashing when I woke up.
Why? There was an interruption in the power overnight. (Root Cause)
Why? There were lightning storms in the area.
Why? Hot and cold clouds in the atmosphere collided.
Why? Barometric changes took place.
Why? The jet stream causes changes to weather patterns.
Why? There are cycles to the seasons on Earth.
Why? The Earth rotates.
So. Determining that the earth rotates takes our series of whys way too far. This is what happens if you keep asking why. (Yes it is exaggerated, but makes the point). You change the context of the problem. If I try to form a countermeasure based on this exercise, the logical one being to change the rotation of the earth, how will that address my problem of being late?-- unless I am Superman of course! I’ve set my sights on something that is not within my control, and I changes the scope of the original problem.
By recognizing that the overnight interruption in power is the root cause of this problem, I can form an effective countermeasure. I can deal with the power interruption by having battery backups. So while I can’t control the outcome of uninterrupted electricity, I can still address and resolve the problem. Going further than this would be a useless foray into issues that are beyond your scope of control.
Finally, as a good way of checking on your 5 Why experience, it’s good practice to ask WHY downward, and THEREFORE upward, as way of establishing Cause and Effect in your chain. This tests the logic. I like to think of it as the "white space" between the whys and we must confirm through gemba visits the sequence of events each are happening or not (turning on or off). This allows us to rule out potential causes and make them most likely. Try it at home or at work, it is always good to practice the whys to condition our thinking past a symptom.
Tracey Richardson - @thetoyotagal
Agile Coach
9 å¹´Thanks for clearly tying 5 whys to the notion of what can and can't be influenced. This blog post is very clear for me. Do you have a similar post on how to handle compound causes?
Dual nationality (UK and US) executive with experience in quality assurance, regulatory affairs, lean six sigma master black belt, operations project and program management
9 å¹´The main principle of the 5 Whys, is not to take the 1st potential cause as the root cause. You should ask as many whys until you have found the potential cause followed up by corrective action, and verification of the action. If you cant turn the issue on and off then you have not found the root cause and should drill down further.
VP Supply Chain | Ops | COO | Private Equity | Interim | M&A | Board | Logistics | Industrial Equipment | Consumer Goods
9 å¹´Good article. LIke most guiding principles, they can be over used if one does not uderstand the context. I would suggest you follow your instincts as to the right numbers of why's. Trust yourself, I am sure you will like the outcome more often than not.
Change and Business Transformation Leader | Centre of Excellence Leader | Digital Transformation | Continuous Improvement | Sustainability| Supply Chain
9 å¹´Tracey...undoubtedly, context/ relevance / curiosity are key ingredients to the whole approach, lest it becomes a mechanical exercise with no though applied. Thanks for the article.
GM Operations | AR Apparels
9 å¹´Nice post.