- 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 has never been replaced. (fourth why)
- Why? - I have not been maintaining my car according to the recommended service schedule. (fifth why, a root cause)
Didn't realize someone (Toyota) codified a technique like this. Inkling is a huge fan of spending the extra steps in root cause analysis of a problem. It's hard to argue when you wouldn't want to at least figure out what the root cause of a problem is, even if you decide to just treat a symptom.
Yet doing the necessary drilling into the problem to get to the root cause often gets neglected. Even happens to us. And we love asking an annoying set of questions about a problem.