Can you really Justify Reliability Centered Maintenance (RCM) - Part I
by Christer Idhammar
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. For examples go to our book store. 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||2x8 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.
I would very much like to hear your comments on RCM and true results that could not have been achieved with less effort. email@example.com attn. Christer Idhammar