Root Cause Failure Analysis (also called, Root Cause Analysis) is indeed great for eliminating the causes of failures with unwanted production, cost, safety and environmental consequences. But don’t stop reading yet. It only deals with failures that have already happened – in fact it is triggered by the very consequences you would have been better off avoiding altogether.
RCFA (RCA) works best if you have chronic (recurring) problems with a pattern that can be discerned through analysis so that the causes of the problems can be eliminated. Eliminate the cause and you eliminate the problem (consequences). It can be used, and often is, for acute (major) problems that don’t occur often, or perhaps haven’t occurred before, but they led to major disruptions. Since these are usually rare events, it’s value is somewhat questionable. Even though it may eliminate future such major events, they were rare to begin with and may never occur anyway!
Regardless of which type of event you want to avoid, recurring or one-offs, root cause methods only work after the fact. They are reactive approaches to achieving high reliability in your operations. Why not be proactive and avoid the failures BEFORE you suffer the consequences?
Some might consider RCFA and RCM (Reliability Centered Maintenance) to be competing methodologies, both aimed at delivering improved reliability performance. Indeed, they do deliver that, but I see them as complimentary rather than competing.
RCM is used to forecast failures that could occur in the future. Those failures are identified using past history (failures that have happened), failures you may already be avoiding through your current Proactive Maintenance program, failures you believe could occur based on your experience in similar systems, and failures you postulate as possible, even though they may not have happened yet. In performing RCM you perform a root cause analysis in order to determine how best to manage those failures. In a sense, RCFA is embedded within RCM. The difference is that it is used before the fact.
RCFA doesn’t forecast failures – it waits until they occur and then deals with them after the fact.
If you are doing your job as Asset or Maintenance Manager, Maintenance Engineer, Reliability Engineer, etc., don’t you want to avoid the problems? The result of your efforts should be sustained reliable performance of the assets. If you wait until after you experience failures before acting to avoid them, are you not being irresponsible. Do your bosses in Operations (Production) really want you to only fix problems after they’ve experienced all the negative consequences of those failures? I doubt it.
RCM works incredibly well on systems being designed – as it does for aircraft. It won’t always catch all possible problems, but it’s better than waiting until after the problems arise, the planes crash and then performing RCFA! You can use it too – on new systems, modifications to existing systems, new equipment installs. You may not catch all the possible failures, but you will most certainly catch most of them.
Existing systems, even those that have been in service a long time, can benefit from RCM. I’ve performed RCM on very old systems where we discovered that over-maintaining was leading to some failures, excessive costs due to PMs that were not needed and some failures that hadn’t yet occurred.
Of course RCM doesn’t come cheaply, but neither does RCFA. Like anything that delivers sustained long term results it requires an up-front investment. In both cases you’ll pay for training, facilitation and team members’ time. You’ll get more reliable performance, lower maintenance costs and increased output capacity (usually this is the real prize)!
The up-front costs of RCM are higher than RCFA, but if you consider the costs of those failures that trigger you to do RCFA, then the picture changes dramatically. With RCFA you will wait for triggering events and their negative consequences. Add those to the cost of training, facilitation and team members’ time and see if it really is less expensive. If you do RCM you can avoid those costs entirely.
I prefer to base my reliability programs on a combination of RCM and RCFA. Perform RCM as early in the life cycle of the asset as you can. The earlier the better. Follow-up with data analysis on failures you’ve dealt with. If you are successful with your RCM efforts, you will be somewhat frustrated at the lack of failure data to analyze – exactly what you want to happen.
If failures occur that you thought your RCM-based program should be avoiding, then use RCFA to fine tune the program. Those failures will provide valuable data points for the analysis and you should have even greater success with your RCFA efforts. If you’ve done a good job with RCM though, you will find that you don’t need to do a lot of this either.