This brings up another problem I see ... some people treat RCA as if it were process improvement. It's not. RCA gets the process (or product or equipment ...) back to where it was before it broke. With process improvement you can simply look at the process, identify opportunities, and implement solutions. With RCA you have to do a much deeper dive in the analysis phase to find out what specific thing(s) actually caused the shift in performance. I liken PI to looking a the process with a magnifying glass, while RCA is looking at it with a microscope. Think of RCA as troubleshooting (which is where I got my first experience, troubleshooting test equipment that had electrical, electronic, hydraulic, pneumatic and mechanical components).