Khun Nittaya,
I agree with your input, it is necessary to have more training to operators and shift foremen in root cause analysis and corrective and preventive action definition, so they can participate as members of the improvement teams providing their ideas an experience, not just support implementation. I would suggest you coordinate with Khun Don and Khun Prasert the best time and way to do that with support from HR – Khun Nopawan.
Regards,