Reliability-centred maintenance and FMEA analysis often go hand in hand, but they are not the same thing. We will explain what an FMEA is, how to apply FMEA in maintenance, and why it makes sense within an RCM program. Plus, don’t forget to download our complete root-cause analysis guide and check other content that can help you implement RCM in your company.
What is FMEA?
FMEA means Failure Modes and Effects Analysis. It’s a versatile root-cause analysis tool, and it assesses how failures may happen and the effects they might have on the system.
FMEA first appeared in the 1940s as a way of improving products and machinery in the military. By the 1950s, it had made its way into the aerospace industry and NASA. But it wasn’t applied in manufacturing until the late 70s.
As a method to avoid risk, FMEA is most effective at the design stage (sometimes styled as DFMEA). That’s when it can identify failures and take action to eliminate, reduce or prevent them in the future.
As a part of a maintenance strategy, FMEA is applied only to a specific piece of equipment. Documenting an asset’s failures is the basis for an effective predictive or preventive maintenance plan because you’ll know which failures to avoid.
So it is not, by any means, a maintenance strategy per se. FMEA is “just” a root-cause analysis tool that you can use to improve your maintenance strategy. In fact, it can be very useful to implement a reliability-centred approach.
What is reliability-centred maintenance (RCM)?
As the name suggests, reliability centred maintenance (RCM) is a strategy that prioritises reliability. It ensures assets are available at any given time with the best possible cost-efficiency ratio.
Like FMEA, a reliability analysis may be performed in the design stages to “design for reliability” and enhance it. However, unlike FMEA, it will address both the expected function and performance. After all, a reliable plant must meet quality standards and avoid production losses.
Therefore, reliability is more than preventing failures. It’s also about reducing the frequency of functional failures and containing their consequences, so as to not compromise the whole system.
At first, managers prioritise key assets. Then they assess their failure modes, which is when FMEA comes in. Afterwards, they adjust their plan accordingly; each task on their program should address a specific failure mode.
Need a refresher? Here’s how to implement Reliability-centred Maintenance step by step.
RCM recommends state-of-the-art predictive maintenance, followed by preventive maintenance and reactive maintenance. The right maintenance strategy for each case is the most cost-effective, which is to say, the one that provides greater reliability with the least investment.
More than “a tool” or “a trend”, RCM is a full-blown maintenance strategy. What sets it apart from other strategies or approaches is its focus on reliability rather than risk, for example.
In fact, RCM is such a complete strategy that it also addresses what happens after a failure. After all, what manager would ignore the mean time to repair, one of the most relevant maintenance KPIs?
When dealing with potential downtime, RCM once again takes criticality, the frequency and the occurrence of failures into account. For example, managers tend to keep spare parts at hand for critical assets. But they might do without them for low priority machines, especially if lead times are reasonable.
RCM is a methodical approach
Another thing that sets FMEA and RCM apart is continuous improvement. Even the best of coaches will adapt their strategy over time. Maintenance managers are no different, and they learn from their mistakes or less than ideal KPIs.
Besides, equipment doesn’t stay the same through the years. A piece of equipment that was once extremely reliable may become unstable with age. Older assets usually require more routine maintenance than when they are at the height of their useful life.
Therefore, RCM is a methodical approach that requires close monitoring. On the other hand, FMEA doesn’t mutate. It doesn’t deal with people or logistics — it focuses on predictable machines. A mechanical failure mode won’t ever change. That’s why FMEA works from the get-go! From the very design stage!
Sure, perhaps we’ll find unexpected failure modes we hadn’t considered before. But if you’re updating FMEAs every year, you’re doing something wrong. Reliability-centred maintenance, however, is an ongoing project. Always.
FMEA and RCM: what’s the connection between them?
FMEA complements RCM. With a thorough failure modes and effects analysis, managers can understand their assets better and implement maintenance strategies that address specific failure modes. (If a maintenance task does not address a specific failure mode, you’re likely wasting time and resources.)
But an FMEA is not a risk assessment, or a maintenance strategy, or even a condition for RCM. It’s certainly one of your best options, but you can choose other root-cause analysis tools to uncover failure modes and how to prevent them. Likewise, performing an FMEA does not qualify as putting RCM into practice.
If you feel like you still don’t have a good grasp of how an FMEA works or how to perform it under an RCM program, we’ve got you covered.
Download our ultimate guide about root-cause analysis and choose what makes the most sense for your operation.
Here’s what you’ll learn:
- 5 RCA tools you need to know, including FMEA
- The advantages and disadvantages of each tool
- How to perform an FMEA analysis step by step
- The difference between an FMEA and an FTA analysis
- And much more about FTAs, Fishbone Diagrams, and 5 Whys.