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Myth Busting 25: We need engineers to do RCM

Myth Busting SeriesReliability Centered Maintenance (RCM) is method for determining the most appropriate failure and consequence management strategies. It deals with your physical assets in your current operating context. The first four questions in the RCM method, are defined in standard, SAE JA-1011, “Evaluation Criteria for Reliability Centered Maintenance (RCM) Processes.” They utilize the time proven engineering method, Failure Modes and Effects Analysis (FMEA).

RCM uses FMEA to get to the level of failure modes and their causes. It identifies failure mechanisms. Few will understand all of those, so Engineering knowledge is beneficial. But if you don’t have engineers, you can still do it.

Knowledge and Experience

The knowledge needed to perform RCM effectively includes asset design and construction, how it is used, and the performance expected. Operators determine how the asset is actually used. They may or may not have technical backgrounds. They need to understand the production process, the asset’s role in it, and how to get it to perform that role. The asset itself and how it works (on the inside) may be an unknown to the operators, but not maintainers.

Most of us reading this article will know how to drive a car safely. We need to know some basic functionality and how to use it correctly, but we don’t need to know how it works. For example, we need to know how to accelerate and stop, steer, signal and park. Yet we don’t need to know how the brakes work, how to accelerator works, how the steering works or how the signals work. We may do some very basic maintenance like cleaning, checking tire wear, and checking fluid levels. Yet most of us leave the rest of the work to our mechanics. They are our maintainers, and we trust them to take care of those systems for us, and to tell us if anything needs extra attention.

Your plant

Plant and mobile equipment operators don’t really need to know how the machinery works. They do need to know how to use it to get the systems they operate to perform. Maintainers know how the machinery and systems work in inside. Often, they do not know how they are used in a production system. For example, your maintainers in a refinery may know how the bottoms pump works, but not how the distillation process works.

RCM requires both sets of knowledge. The first question in RCM is about functions – something that only the operators can truly answer. When we look at failure modes and what to do about them, we need the maintainer’s knowledge. Describing effects of failure modes requires both. Sometimes the failure cannot be prevented nor predicted. We then get out of the realm of the maintainer and may get into the realm of the designer. The timing of proactive tasks can be set to minimize or eliminate operational disruption.  Again, we need operational knowledge to set that timing properly.

Who has the knowledge?

The main bodies of knowledge and experience need to come from operators and maintainers. Even for newly designed systems with little or no operating history, operators and maintainers of similar systems know enough for the analysis. Engineers, are very helpful with their asset specific knowledge, their ability with the math when determining task frequencies and their passion for digging into details. Even the most diligent of maintainers can miss that. So engineers add value.

But do you need engineers for RCM? The answer is “no but”. The main contributors are operators and maintainers. Engineers are helpful but even without them, the analyses can still be thorough and rigorous. The facilitator is the real key to that.

How many engineers?

Should you trust your RCM work to engineers alone? No. Unless your engineer has both operational and maintenance experience, they can come up short on the insights needed in doing RCM properly. Occasionally I see RCM left in the hands of engineers to perform. In my opinion that is a mistake, particularly if using more junior engineers. Their lack of practical experience will show up as either superficial analysis, or excessively detailed analysis. Both result from a lack of practical application knowledge. In my experience, any RCM analysis performed by only one person (regardless of background) will likely be flawed.

Can you use multiple engineers? Yes. Ideally they will have complimentary knowledge. For example a maintenance engineer coupled with a process engineer could do a very good analysis, but they would still benefit from the hands on experience of maintainers and operators. You can’t get around it – that field experience is the most valuable contributor in an RCM analysis.

Can you have too many engineers involved? Yes. I’ve seen this happen where engineers that had similar expertise. Perhaps personalities played a role here, but they had a bit of an intellectual rivalry. In their bids to out-do each other, they came up with increasingly rare, yet plausible failure modes, almost all of which resulted in Run-to-failure decisions. In that case we did have experienced maintainers and operators in the analysis team, they could see where it was headed long before we finished identifying all the exotic failure modes, but we were powerless to stop it.

Both engineers were respected, considered experts, and no one dared second guess them. The analysis took a few days longer than necessary, was academically brilliant, yet little real value was added. I’m always careful with my RCM team selection making sure we have a balance of knowledge and expertise at the table and little to no duplication or overlap.


So in conclusion, you benefit from engineers in RCM, but the real critical information comes from the maintainers and the operators. The facilitator ensures the needed information is used properly and can even identify where extra help may be needed.