coderly / process

The Coderly team's process documentation.
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Five whys #49

Closed venkatd closed 8 years ago

venkatd commented 9 years ago

I see a lot of similarities between how Toyota operates and how we have started to operate. They implement thousands of micro-improvements every year in their process and assembly lines. Most of the improvement suggestions come from people working on the front lines.

One interesting thing they do is called the 5 Whys

The vehicle will not start. (the problem) 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) The questioning for this example could be taken further to a sixth, seventh, or higher level, but five iterations of asking why is generally sufficient to get to a root cause. The key is to encourage the trouble-shooter to avoid assumptions and logic traps and instead trace the chain of causality in direct increments from the effect through any layers of abstraction to a root cause that still has some connection to the original problem. Note that, in this example, the fifth why suggests a broken process or an alterable behaviour, which is indicative of reaching the root-cause level.

This is something that Toyota does to identify problems and get to the root cause of the problem.

My suggestion is as follows: