Don’t just probe…ask the five ‘whys’


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To get to root cause of any problem requires probing – you have to ask the right questions. And the most important question to ask is why. But it’s not enough to ask this question once; you have ask it over and over. Asking why
leads to new insights that help solve problems. Asking why can also evoke strong reactions from the questioned, along with an occasional defensiveness and hostility. But it needs to be asked.

Notwithstanding their current problems, Toyota has been the leader over the past thirty years in the development of this type of thinking. They rose to the top of the auto industry in part, by their emphasis on this type of tireless probing. In his book on the Toyota production system, Taiichi Ohno introduced the practice of ‘the five whys’. The process of asking ‘why’ (at least) five times allowed Toyota to discover root causes and solve many of the problems faced by their competitors – competitors who didn’t have the same discipline and thus, were unable to solve the same problems. It was (and still is) a huge competitive advantage for Toyota. Here’s a simple example that highlights this technique to probe why a machine stopped functioning. [1]

1. Why did the machine stop functioning?

“There was an overload, and the fuse blew.”

2. Why was there an overload?

“Because the bearing was not lubricated properly.”

3. Why was the lubrication not sufficient?

“Because the lubrication pump was not pumping sufficiently.”

4. Why was it not pumping sufficiently?

“Because the pump shaft was worn, and it was rattling.”

5. Why was the shaft worn out?

“Because there was no strainer attached, and this caused metal scrap to get in.”

These five questions were required to find the solution; to have stopped anywhere in the process would have ensured that the root cause never would have been found. Most others would have simply replaced the fuse; a small minority would have focused on the lubrication system. Only Toyota would have discovered that the solution required the addition of just a simple strainer.

But under the heading of ‘easier said than done’, this type of probing is not easy. According to Jonathan Isaacs of the Boston Consulting Group, “…to pursue such probing takes a special, strongly motivated person… Asking why five times is easy to say but hard to do. It challenges people’s knowledge and even self-respect. It can call into question their diligence and the basis of their expertise. It requires fresh thinking on all sides. Yet’ it’s so basic to learning, to seeing new things from the familiar.” [2]

Here’s the takeaway: As Issacs so eloquently puts it, “asking why can raise questions that are fundamental, but not necessarily answerable through rigorous analysis itself. There are the basic questions of leadership and common sense. They are the search for the point.” Does your organization have the strength of leadership to ask these types of tough questions? It’s better to find out sooner rather than later.

[1] Taiichi Ohno, Toyota Production System–Aiming at an Off-Scale Management
(Tokyo; Diamond Inc., 1978)

[2] The Boston Consulting Group, On Strategy (Hoboken, NJ: John Wiley & Sons, Inc., 2006) p. 367


Republished with author's permission from original post.

Patrick Lefler
Patrick Lefler is the founder of The Spruance Group -- a management consultancy that helps growing companies grow faster by providing unique value at the product level: specifically product marketing, pricing, and innovation. He is a former Marine Corps officer; a graduate of both Annapolis and The Wharton School, and has over twenty years of industry expertise.


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