Reliability Centered Maintenance (RCM) was developed in the airline industry to be used for developing maintenance programs for new aircraft. There’s no doubting it – originally RCM was intended for new designs and arguably where the results of failure could be catastrophic, specifically the loss of life and where costs of maintaining had grown ridiculously high. Aircraft maintenance costs had indeed grown very high by the 1960’s and 70’s before RCM came along. In fact, one of the big drivers behind RCM was cost reduction. It worked too – in both the aerospace and nuclear power industries! Safety and other benefits were there too, but they were not primary drivers. Then, as today, cost was the problem that got the attention.
Since then we’ve seen RCM evolve and add in risk based decision making (as opposed to just the original cost based criteria). That makes it more amenable to dealing with failures where risks other than spending, are at stake. Safety and environmental considerations could be taken into account and the justification for tasks can be based on risk reduction not just cost. Today it deals with both costs and risks very well. But when should it be applied?
Those of us who understand asset management concepts and life cycle costing, will know that the best opportunity to influence life cycle costs exists at the design stages. Decisions made at the earliest stages of an asset’s life cycle can have profound effect on how long the asset will last, how well it will perform, how much it will cost its owners, how much revenue it can create or service it can deliver. It follows logically that decisions made about those assets, including their reliability and maintenance features, will also have profound effect on future costs (and risks). The best time to apply RCM is indeed at the design stages.
Even without detailed design drawings, the conceptual designs can be subjected to RCM analysis and decisions made. Those decisions can influence design as well as future support and outcomes. As design details becomes better defined and refined, those decisions can become more specific – to the point of defining your future maintenance program, and some of the operator tasks. There is a terrific opportunity then to leverage that definition of what must be done, how often and by whom into a complete definition of all support resources that will be needed.
That leveraging (combined with RCM) is known in military circles as “Integrated Logistics Support”. Without it, militaries would be hard pressed to field systems and support them as successfully as they do. For the most part we don’t do that in industry and we struggle with support challenges from commissioning onwards. That’s another discussion though.
So, if RCM is best applied at the design stages (as it was designed to do), then is there value in doing it later in the life cycle of the asset? Quick answer – yes!
Indeed the potential benefit of RCM diminishes as the asset ages throughout its life cycle, but there is still value that can far exceed the costs of implementing RCM, particularly if you apply it with your most critical assets – those that generate the most value.
Without RCM, maintenance programs tend to be at least partially ineffective. System and asset performance doesn’t quite achieve what was expected and costs to maintain them can be high. Manufacturer recommended maintenance is rarely tailored to your operating needs and misses the mark. Strict adherence to those programs (usually a rarity) will result in excessive costs. Excessive reliance on shutdowns and preventive routines are usually poor matches to the assets’ needs. Of course poor maintenance work execution discipline will mean that proactive maintenance is generally not done at all, so costs are high and reliability is low.
There is a spectrum of how proactive your maintenance program can be – from zero (entirely reactive) to very high (too many overhauls, shutdowns and PMs) has quite an impact on both reliability and costs. Cost are high at both ends of the spectrum. Reliability will be low at the reactive end and disappointing at the high end. There is a point, in the middle, where the mix of preventive, predictive, detective, operator tasks and running to failure is optimal. RCM is how you determine that mix.
I’ve worked with many companies that are highly reactive. In all cases, where RCM has been applied, costs have come down and reliability improved. Maintenance costs shift from reactive work to proactive and can fall substantially as a result, eliminating the need for contractors and overtime. The big benefits arise from the improved reliability. In one plant which was struggling with periods of low demand, the increased capacity enabled them to eliminate a production shift. In most cases, where demand is high, the increased capacity translates into increased revenues and greater margins.
In the few cases where I’ve seen extremely high levels of compliance with manufacturers’ programs, I have seen costs come down and reliability improve. In one case, an electric utility, costs came down by 22%. RCM will eliminate excessive or ineffective work. It will add work that is needed. It always drives you towards that optimum point where the mix of actions and frequencies is optimized.
If you are very near the end of the asset life and disposal or permanent shutdown is looming, then I wouldn’t bother with RCM. You might as well end things as they’ve been. But seriously consider it for the replacement system if there is going to be one. Clearly, benefits diminish with the age and remaining life of the asset, but in other cases, the costs of doing RCM can be dwarfed by the benefits in cost reductions and revenue gains, both of which will be sustained year over year.