What does “root” means? for example, a network connection down because of network card is broken. This is “root” or we need to dig deeper to find out why the card is broken….how many “why” we should ask…
I have heard of the 5 Questions rule of thumb for determining Root Cause:
What happened? The network went down
Why? A server’s network card failed
Why? The card overheated
Why? There was dust coating the card
Why? The floors in the server room are never vacuumed
Why? There is a policy against letting cleaning crews into the data center due to the sensitive nature of the equipment
So what is the root cause of the failure? A policy that is preventing the floors from being cleaned.
Again, it’s just a simple rule of thumb that can be taken less far or even further.