Can You Really Justify Reliability Centered Maintenance (RCM)?
Christer Idhammar, Founder IDCON INC
As a result of this column I am risking to receive critique, but also to be given feed back expressing relief from readers whose beliefs are similar to mine. That is always the case when I write about Reliability Centered Maintenance (RCM.
What is Reliability Centered Maintenance?
Reliability Centered Maintenance is a step-by-step instructional tool for how to analyze a system’s failure modes and define how to prevent or find those failures early. RCM become a very detailed study of things we already know, you will often hear the justification “it’s to make sure we don’t miss anything.” If you are considering implementing a reliability centered maintenance program, you. should be aware of the problems you may run into.
A main problem is that an RCM study tends to require 4-5 individuals a week per system, which a common sense approach with standards would only require one individual for 1-2 hours for the same task.
IDCON has mentioned in several articles that Reliability Centered Maintenance is overkill for most plants when they are trying to improve their preventive maintenance program.
Does this mean IDCON is trying to say RCM is a useless tool? Absolutely not!
Reliability Centered Maintenance can be a very useful tool in several situations. In fact, IDCON conducts RCM training for clients who are improving their overall Preventive Maintenance programs. Here is a short list of situations where we agree it can be very useful:
- when designing, selecting, and installing new systems in a plant
- when setting up preventive maintenance for complex equipment and systems we are not clear on how to work
- when teaching people the basic of reliability – it helps explain the matters in a detailed fashion
- DO NOT USE when defining preventive maintenance for typical plant equipment such as pumps, motors, couplings, cylinders, hydraulic, etc. – it’s too tedious, we know this equipment and failure modes
However, DO NOT USE when defining preventive maintenance for typical plant equipment such as pumps, motors, couplings, cylinders, hydraulic, etc. the method is too tedious, we all know this equipment and failure modes.
Can you really justify Reliability Centered Maintenance?
I recently participated in a meeting to design a reliability and maintenance conference. Twenty-seven people, mostly from plant maintenance and operations organizations, attended the meeting. On the first day, we brainstormed topics for the conference including: Planning and Scheduling, Preventive Maintenance, Root Cause Problem Elimination, Shut Down Management, Spare Parts Management, etc.
Then someone mentioned Reliability Centered Maintenance as a possible case study. After a period of silence an operations manager cautiously asked if people still believe that RCM programs can pay off. He mentioned his plants team has been trained in RCM methodology and then spent significant time performing analyses only to gather obvious results and already practiced preventive maintenance and operations tasks. Several other meeting attendees had the same experience and the topic of RCM was not included in the conference agenda.
For me, this was encouraging to hear, Reliability Centered Maintenance has always reminded me about the parable “The Emperor’s New Clothes” by HC Andersen. Sooner or later someone will ask for substantial results and these results could have been delivered at a fraction of the cost.
I have always believed and proclaimed that there is a place for Reliability Centered Maintenance in early equipment design and for complex manufacturing systems. We have proven over and over again that for more than 95% of manufacturing systems applying this method cannot be justified because known standards can be applied to most equipment components.
However, for over 30 years, I have used one part of Reliability Centered Maintenance myself: the theory of failure distribution and time for failures to develop breakdowns. I never knew it was RCM, always thought of it as plain old common sense.
Before the meeting I mentioned above, I had just completed an evaluation of results from an ongoing Reliability Centered Maintenance initiative in a plant in Europe. The organization was very proud of their accomplishments. Teams of 8-11 employees worked a total average of 600 person hours on each analysis. Each analysis was documented in comprehensive reports with recommended actions to improve reliability. The outcome of this work included the following recommendations:
|Equipment identification||Skill||Frequency||Action||Time required|
|353-001 Brine pump||PdM/Va||3 months||Vibration Analysis||4 Hrs|
|353-002 Brine Pump||PdM/Va||3 months||Vibration Analysis||4 Hrs|
|546-048 Gear Box||PdM/OA||4 weeks||Oil testing Wear Particle Analysis||2 Hrs|
|546-048 Gear Couplings||Mech||1 year||Disassemble and inspect for wear||2×8 Hrs|
|546-048 Motor||El||1 year||Insulation Test||1 Hour|
|546-048 Starter||PdM/IR||1 year||Thermograph test of starters||2 Hours|
It doesn’t take an expert to realize that all of the above recommendations are obvious actions that must be completed. It is also apparent that the frequencies are incorrect and the time to complete the job is way too long.
For example, it is necessary to perform vibration analysis on a critical bearing more frequently than every 3 months. In most cases, it should be performed every 2 weeks and it doesn’t make more than an average of 5-10 minutes.
Oil testing frequency is realistic but it does not take two hours to complete.
Gear couplings do not need to be disassembled once a year, they can be tested on the run with stroboscope and an IR gun in less than five minutes.
The thermograph test of the motor and starter should be done more frequently because the failure developing period is shorter than one year.
After reviewing the results from the Reliability Centered Maintenance analysis I visited the Predictive Maintenance group and asked what had changed. They shook their heads and said that if they followed the recommendations of the RCM teams, “things would fall apart here.” “We do all these things already, but we have the right frequencies.”
I was very upset when I saw what was going on here, how can management fall into this trap and be blinded with the fancy reports and the often faulty recommendations?
This organization could have spent the time and money to upgrade their existing systems, technologies and skills. They could have invested in training for their operators to do many needed basic inspections of equipment.
It’s not just my opinion, others agree
Solution Magazine’s poll from October 19, 2005 also confirms that very few organizations, if any, uses complete Reliability Centered Maintenance analysis. Less than 7% answered that they use RCM regularly and 56% answered that they tried it but do not use it anymore.
Below are written responses from three readers:
“Good article and I agree fully. Reliability Centered Maintenance has its place in things like aircraft design. One large industrial plant put thousands of man-hours into it and claimed great results, but a visit to their plant showed that their calculations of benefits was based on assumptions, not hard numbers and they would not allow entry to the plant to talk to their craftspeople. I also think they started from a low point and good PM/ECCM would have achieved the same results. On the other hand, everyone who is responsible for maintenance should read Moubray’s book “RCM II”. It’s the most logical approach to maintenance that I’ve ever read, and while it doesn’t need to be applied in detail, the concepts are great.” –Don A
“I read you article and agree very closely with your position on Reliability Centered Maintenance. Prior to working in the paper industry, I worked in a Nuclear Power Plant. We went through an RCM type maintenance evaluation and the results were similar. It just amounted to a standardized table of easily identified failure modes and the actions to prevent or detect them. It looked very similar (to) the example in the article. At least I was able to get the right frequencies put in for the predictive maintenance work I was doing at the time. It did look like a good way to make some easy money if you can get a contract for an RCM analysis. One additional point I would make about RCM that was not in your article is that the general theory is very good for anyone in maintenance to understand. Working through some rigid RCM examples in the early stages of learning the maintenance profession does help drive the concepts home. In that respect, I would recommend it as a good training tool for career maintenance professionals. The training should also include how to take these concepts and use them in a practical and affordable way. Many maintenance departments have a variety of PMs on the books that were created when something failed and they had to do something about it. When we go through RCFA analysis of a failure at the (–) mill, I often use RCM type logic when someone offers up another PM as the answer to our problem. I basically ask exactly what the failure modes we are trying to prevent are and will this PM proposal accomplish that. This tactic has allowed me to kill a lot of bad PM proposals and create some good ones. It only takes a few minutes of brainstorming and some arguing and the process done.” –James J.
“I too have encountered many paper sites where they have tried to apply all of the principles of RCM (classical) and have failed to produce any meaningful results, in fact, in most cases, NO results, but with plenty of costly effort. I believe there is a place for the ‘plain common sense’ aspects of the Reliability Centered Maintenance process, but obviously these have to be applied with moderation and show a return in the investment. As the old saying goes, it’s not the process (journey), it’s the output (destination) that is the objective. Too often I think we get caught up in the process.” –John Yolton.
I would very much like to hear your comments on Reliability Centered Maintenance and true results that could not have been achieved with less effort. Contribute your thoughts to the Maintenance World Discussion group.
Interested in learning more about the RCM Trap?