As a result of this column I am risking to receive critique, but also to be given feed back expressing relief from readers who believe like I do.
That is always the case when I write something about RCM (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.
The first day we brainstormed to come up with topics for the conference.
The classic subjects including: Planning and Scheduling, Preventive Maintenance, Root Cause Problem Elimination, Shut Down Management, Spare Parts Management, etc. were agreed upon to be included in the conference program.
Then someone mentioned RCM as a possible case study.
After a period of silence an operations manager asked cautiously if people still believed that RCM programs can pay off.
In his plant teams had been trained in RCM methodology and then spent significant time to do analyses that only resulted in obvious and already practiced preventive operations and maintenance tasks. Several other meeting attendees had the same experience and the topic of RCM was not included in the conference agenda.
Four years ago this topic was very well covered in the same conference but already then the interest had started to fade away according to conference evaluations.
To me this was very encouraging to hear. RCM 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 if these results could not have been delivered at the fraction of the cost of the RCM analysis.
I always believed and proclaimed, in many other articles, that there is a place for RCM in early equipment design and for very complex manufacturing systems. We have proven over and over again that for more than 95% of manufacturing systems that applying this methodology cannot be justified because known standards can be applied to most equipment components.
One part of RCM I myself have used for over 30 years is the theory of failure distribution and time for failures to develop to break downs. I never knew it was RCM, I always thought of it as plain common sense.
Before this meeting, I had just completed an evaluation of results from an ongoing RCM initiative in a plant in Europe. The organization was very proud of their accomplishments.
Teams of between eight and eleven employees worked a total average of 600 person hours on each analysis. Each analysis was documented in very 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|
You do not need to be much of an expert to see that all of the above actions are obvious to do. It is also apparent that frequencies are wrong and time required to do the job is way too long.
For example, to do Vibration Analysis on a critical bearing every three months is way too infrequently, it should be done every two weeks and it does not take more than an average of about five minutes, not four hours.
Oil testing frequency is realistic but it does not take two hours to do.
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 RCM 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 and technologies and skills. They could for example involve and train their operators to do many needed basic inspections of equipment.
FEEDBACK FROM OTHERS
Solution Magazine’s poll October 19, 2005 also confirms that very few organizations, if any, uses complete RCM analysis. Less than 7% answered that they use RCM regularly and 56% answered that they tried it but do not use it anymore. (October 31, 2005)
Below are written responses from three readers:
“Good article and I agree fully. RCM 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”. Its 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 RCM. 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 any one 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 RCM 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. (He has agreed to include his name)
I would very much like to hear your comments on RCM and true results that could not have been achieved with less effort. firstname.lastname@example.org attn. Christer Idhammar