You are correct, Marcelo, in listing the items in ISO 9001. However, the standard does not say the steps need to be done in that specific sequence. Also, when we pay close attention to the ISO 9001 text, we note that the standard does not use the term ROOT cause. Just cause(s). In the real world, we all know that EFFECTIVE (ROOT) cause analysis are rare. Most organizations out there focus on correction and very few do an effective job of investigating in depth ROOT causes, so TRUE corrective action can be enabled.
If we forget ISO 9001 for a minute, do you believe there is value in going through a (root) cause analysis for a non-repetitive, non-critical, trivial issue? In my opinion, it does not. Finally, we must realize that even standards have flaws. For example, it looks like ISO (including the TC 176) finally realized the problems with the concept of preventive action, as written, in the current ISO 9001 standard. For those who attended the ISO 9001:2015 revision webinar by Dr. Nigel Croft (chair SC2 TC 176), we heard that the next version of ISO 9001 will no longer have the requirement for PA, as currently defined.