Most of the corrective action reports, I had come across in my life, had the actions mentioned as providing training to operators and staff, displaying one-point lessons, or creating awareness about the issues. Without a doubt, the root causes were always a lack of awareness. If an employee commits a mistake it is because of his lack of awareness. If a manager not properly reviews the document it is because of his lack of awareness and the list that is going on.
It is the easiest way to conclude a corrective action with training. Because people are not willing to deep dive into the ocean of complexities existing within the organization and identify the core conflicts. They intuitively know that this is not the right root cause, but they comfortably end it with a lack of awareness and training.
The non-conformities identified in the system are to be seen as interrelated and independent activities instead of looking at in silos. They could be the changes in any other element in the system which you may not be aware of. The research was done in minimizing human error revealed that 99% of accidents begin with human errors, but the root causes of these accidents are weaknesses within the management system. So, lack of training is not the solution to many problems. Instead one must have the courage to go to the root without any bias or false assumptions to see clearly what prevents them to achieve it.