Method mastery: The five whys

The five whys technique is useful in getting to the root cause of a problem. A bit like peeling the layers of an onion, each time we ask why, we get closer to the heart of the matter. The more I’ve used the five whys technique in human centered design for all sorts of challenges, the more I am a fan of it. I’ve also experienced how tricky it can be to explain it and to use it, depending on the context.

At times stepping through the five whys has been foggy. “Are we headed in the right direction?” “Are we getting closer to the root cause?” Five whys makes an appearance in countless design thinking toolkits and method sets, however the guidance on using it is often quite cursory.

The technique was first used on the Toyota factory floor, thanks to Taiichi Ohno--inventor of the Toyota Production System and Lean manufacturing. He stated: “Having no problems is the biggest problem of all.” Ohno saw a problem not as a negative, but “a kaizen (continuous improvement) opportunity in disguise.” He coached his stuff: “Ask ‘why’ five times about every matter.”

In my experience there are three “tricks” to making this technique effective. The first, in my opinion, is the most critical.

1. How we phrase “Why…?” Makes a difference.

Sometimes, just asking “Why?” works, and other times, the question needs a little more framing. Asking “Why?” can be too open-ended. What statement starters could we use to dig in to understand the cause? Here are the phrases we’ve tested out to get to the cause:

• Why do we have this problem?

• Why is that happening?

• Why is that stopping us?

  And lastly…

• Why is that important?

Starting off with a run of the mill parent challenge (and one that I happened to have this week)… “Why haven’t you completed your Spanish homework?” Let’s work it through with a few of these different phrases. If you see an X, it’s because there was just nothing, nada in response to that question!

Okay, humour aside, some of the lines of questioning were not that helpful. So what worked and what didn’t? In this case the root cause was the lack of a Spanish-English dictionary. We can turn that into a challenge statement, something like “How might we translate Spanish to English without a dictionary at home?” Solutions could be sourcing an online dictionary, downloading an app, or calling a friend.

But just asking “Why?” didn’t get us to the pointy end of the problem. It was the phrasing “Why do we have this problem?” and “Why is that happening?” that got us there, and fairly quickly too. Just asking “Why?” was not that helpful.

Let’s try a different problem, in the space of money management. Let’s assume we’ve interviewed someone who wants to “get ahead” and save to buy a home, but is not currently saving at all. (Recount of a real conversation).

All of the end points are relevant, but if we have the focus on how to change behaviour, or why behaviour is not there at the moment, “Why?” doesn’t get us to the depth that the other question phrasings do.

In the last example we start with a problem of very low representation of women in a leadership team. Cutting to the chase, the final “cause” for each question is as below:

This reflects real discussions. As before, several of the end points are potential root causes. But the scale differs dramatically- stereotypes are definitely a factor but that is at the society level, while lack of engagement across the organisation and shifting the way of working are at the company level, they are within the stakeholders’ control. The big “Why?” is so big, it’s bigger than us. Asking “Why do we have this problem?” and “Why is that stopping us?” brings the problem into proximity, into our orbit and our influence to solve.

One of the criticisms of the five whys is that a different group of people could well arrive at a different root cause. Allowing for the nuance of question phrasing and interpretation, this exercise shows how that could easily happen.

2. Checking the logic

Once we’ve asked why five times and captured answers, back checking the logic can help us pinpoint where things might have gone off tangent.

We start with the last statement, add the word “because” and make sure that the statements connect. Because of the stereotype, women are seen as gentler, because of this, they’ve tended to have carer roles, and because of this men have been in leadership roles and thus are seen as better leaders.

Or, because I see my parents with so much responsibility (that I’m not ready for), they are living are dull life, and because of this, in contrast I feel I have my whole life ahead of me. So I’m not worried about saving, it will happen one day, and as a result, I haven’t created a budget.

Working backwards through the logic can help us to finetune the cause and effect structure. It’s even better if we can do this as we work through each Why. This exercise has also highlighted how there may be more than one root cause. Asking the question with a different framing can help to bring out the difference causes.

3. It helps to have a sense of the “end of the line”

The main benefits of using the Five Whys is not only to identify the root cause of a problem, but also to determine the relationship between different root causes. Having domain expertise helps to navigate the relationship. Domain expertise may be in manufacturing, in service delivery, or changing human behaviour.

For example if we are trying to understand the real drivers of human behaviour it helps to have a model of behaviour in mind. We might for example, be searching for motivations, and understand what tensions exist. In the case of the second example, the person who wants to save for their first home, but hasn’t yet started, the motivational tension is between the person’s own aspirations to “be a grownup” building their financial future, and their need to be part of the social group, living in the now. The other answers provide context, including the ability that the person has (they don’t know how to start), and the opportunities and triggers that may be the clue to change.

When we use Five Whys to get to the cause of behaviour, the deep digging should yield an enabling insight, an important understanding about people’s beliefs and motivations that may be
important in planning behaviour change.

In the third example, having knowledge of the field of gender equality, workplace diversity and inclusion strategy, and culture helps us to navigate the cause outputs and be able to order them in relationship and significance.

Since the original Five Why’s method was shared, we’ve seen fishbone diagrams add structure and frame specific focus areas of enquiry. If the field is manufacturing, the 4Ps approach may help, prompting us to ask Why along four lines of enquiry: Policies, Procedures, People and Plant. The 4Ss framework may help with the service industry: asking Why for Surroundings, Suppliers, Systems and Skills.

Maybe every level, every answer, is of value. Knowing the subject area helps in working out – is the problem to do with process, to do with people, to do with some other aspect?

Like most group problem discovery techniqueS - it’s organic! But here’s what WE SHOULD keep in mind

The framing of the why question matters a whole lot. Knowing what you are searching for, the end of the line of logic, is helpful. It may take five whys, it make take only three. Finally, checking the logic - the cause and effect relationship - at each step helps too.

Plus there’s a watchout. In finding the problem, we have to be careful we are not also describing the solution. These are two different things. One of the fundamentals of human centered design is understanding the problem before we attempt to solve it.

Links and supporting information

Taiichi Ohno--inventor of the Toyota Production System and Lean manufacturing. He stated: “Having no problems is the biggest problem of all.” Ohno saw a problem not as a negative, but, in fact, as “a kaizen (continuous improvement) opportunity in disguise.” Whenever one cropped up, he encouraged his staff to explore problems first-hand until the root causes were found. “Observe the production floor without preconceptions,” he would advise. “Ask ‘why’ five times about every matter.” This video gives more detail https://www.youtube.com/watch?v=SrlYkx41wEE

The Jefferson Memorial example is often quoted https://www.youtube.com/watch?v=BEQvq99PZwo
Very examples of using a Fishbone (or Ishikawa) Diagram to Perform 5-why Analysis https://www.bulsuk.com/2009/08/using-fishbone-diagram-to-perform-5-why.html#more
And for something humorous (My daughter loves this. She doesn’t understand it, but she loves it!) https://www.youtube.com/watch?v=7q89tdSjE-0&gl=SG