In the first principles mental model earlier, the procedure to reach the fundamentals was simple: asking the right questions. Meanwhile, in the current mission, we said, “mistakes are the greatest teacher.”
If we connect these two ideas, the question is: What is the best question to ask our “teacher?” How can we learn the most?
Ask “5 Whys?”
“5 Whys” is an iterative interrogative method to explore the cause-and-effect relationships underlying a particular problem. The goal is to reach the root cause of a problem or mistake.
This method was developed by Sakichi Toyoda during the early years of Toyota Motor Corporation, as a key pillar of their problem-solving philosophy when its manufacturing processes were still nascent. The biggest benefit of this method, just like Socratic Questioning was to reveal the true nature of the problem, so that the solution is illuminated itself.
Consider this example for the problem: “The vehicle is not starting.”
Why? – The battery is dead. (First why)
Why? – The alternator is not functioning. (Second why)
Why? – The alternator belt has broken. (Third why)
Why? – The alternator belt was well beyond its useful service life and not replaced. (Fourth why)
Why? – The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause)
Note that these answers should have a cause-and-effect relationship when read in reverse, i.e., the last issue must lead to the previous, and so on.
P.S.: The 5 Whys method is flexible in that sometimes you may reach the root cause in the third Why itself, or sometimes even 7 may be needed. Also, it serves as a great tool for introspection and uncovering our biases.