I just had the opportunity to attend a root cause analysis (RCA) class in Australia. The class was run by the Strategic Industry Research Foundation for a port coal-loading facility.
I know this is a column in a magazine for fleet maintainers, and port coal-loading facilities don't have much to do with trucks. But I like all big equipment. And port equipment is big. The piers in Australia can load 8,000 tons of coal an hour into ships bound for China. Ten hours per ship and three ships at a time.
In the RCA class were the port's maintenance mechanics and electricians. This was significant since I thought attendwees would be managers and engineers. The students were told to bring to the table various problems they saw in their everyday maintenance life.
The instructor, Bernie Piovesan, took the class through a structured learning experience where the students eventually got to address the issues they brought to the table. Using flip charts and Post-it Notes, the students, broken into teams, wrestled with the causes to their problems.
As the teams struggled with the RCA steps, they started to travel down the roots of their various problems. People's faces lit up as they started to see the real causes of the problem and what they could do to solve it forever. The instructor had to hold the people back from jumping to conclusions because the discipline helped find more universal causes.
After that class I thought this RCA must be pretty powerful and started to train myself in the approach. Since I talk about lean maintenance, operator maintenance, PM and other topics, a universal approach to solving problems would be universally useful.
I saw RCA as sort of a universal tool, kind of like a pry bar which can be used for lots of different things.
Think about this. If there was a management tool that is a key to PM improvement, reliability centered maintenance (RCM), continuous improvement, lean maintenance, total productive maintenance (TPM), troubleshooting and safety, and that management tool could, and should, be applied by workers, wouldn't you want to learn it? It turns out there is such a universal tool and it's called root cause analysis.
Simply speaking, RCA is a structured three-part approach. First - evaluating the consequences of the problem while isolating the problem. Second - finding the causes of a problem. Third - intervening to stop that chain of events that caused the failure or accident.
According to Piovesan, although the process is called root cause analysis, it might be more properly called cause analysis. The reason being: generally there are multiple "cause trees" or sequence of events that lead to any substantive failure under analysis. Each failure or event has several cause trees and several potential causes. An intervention in the cause tree that is economic, stops the failure and has no bad unintended side effects is the root cause.
Why call RCA a universal tool? It could be said that maintenance is made up of a hundred problems a day. Good maintenance professionals can solve most of them at the first shot without too much suffering. But typically, there are some problems that defy the easy way and lend themselves to a more structured approach. There are also problems wherein maintenance professionals fix the symptoms but never get deep enough into the problems to solve them forever.
For example, what if one class of trucks got significantly lower mpg and consumed tires faster than other units of the same size? We might just change the tires more often and yell at the drivers to be more careful. Using RCA, we would first figure out how expensive the problem is. Then, we would identify all the causes and look at the causes of those causes.
The causes of the causes become the cause tree. The key is to look closely at what intervention will interrupt the cause tree and eliminate the problem forever, or significantly reduce the probability of the event.
It's about principles of reasoning