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Reliability Centered Maintenance

RCM finds its early roots in the early 1960's. The initial development work was done by the North American civil aviation industry. It came into being when the airlines at that time began to realize that many of their maintenance philosophies were not only expensive but also actively dangerous. This realization prompted the industry to put together a series of "Maintenance Steering Groups" to re-examine everything they were doing to keep their aircraft airborne. These groups consisted of representatives of the aircraft manufacturers, the airlines and the FAA.

The first attempt at a rational, zero-based process for formulating maintenance strategies was promulgated by the Air Transport Association in Washington DC in 1968. The first attempt is now known as MSG 1 (from the first letters of Maintenance Steering Group). A refinement - now known as MSG 2 was promulgated in 1970.

In the mid-1970’s the US Department of Defense wanted to know more about the then state of aviation maintenance. They commissioned a report on the subject from the aviation industry. This report was written by Stanley Nowlan and Howard Heap of United Airlines. They gave it the title “Reliability Centered Maintenance”. The report was published in 1978, and it is still one of the most important documents – if not the most important – in the history of physical asset management. It is available from the US Government National Technical Information Service, Springfield, Virginia.

Nowlan and Heap’s report represented a considerable advance on MSG 2 thinking. It was used as a basis for MSG 3, which was promulgated in 1980. MSG 3 has since been revised twice. Revision 1 was issued in 1988 and revision 2 in 1993. It is used to this day to develop prior-to-service maintenance programs for new aircraft types (recently including the Boeing 777 and the Airbus 330/340)

Copies of MSG 3 revision 2 are available from the Air Transport Association, Washington DC.

Nowlan and Heap’s report and MSG 3 have since been used as a basis for various military RCM standards, and for non-aviation derivatives. Of these, by far the most widely used in RCM2.

RCM2

RCM2 is a process used to determine what must be done to ensure that any physical asset, system or process continues to do whatever its users want it to do.

What users expect from their assets is defined in terms of primary performance parameters such as output, throughput, speed, range and carrying capacity. Where relevant, the RCM2 process also defines what users want in terms of risk (safety, environmental integrity), quality (precision, accuracy, consistency and stability), control, comfort, containment, economy, customer service and so on.

The next step in the RCM2 process is to identify ways in which the system can fail to live up to these expectations (failed states), followed by an FMEA (failure modes and effects analysis), to identify all events which are reasonably likely to cause each failed state.

Finally, the RCM2 process seeks to identify a suitable failure management policy for dealing with each failure mode in light of its consequences and technical characteristics. Failure management policy options include:

predictive maintenance
preventive maintenance
failure-finding
change the design or configuration of the system
change the way the system is operated
run-to-failure

The RCM2 process provides powerful rules for deciding whether any failure management policy is technically feasible or worth doing. It also provides precise criteria for deciding how often routine tasks should be done.

Heavy emphasis on the expectations of the user is one of the many features of RCM2 which distinguish it from other less rigorous interpretations of the RCM philosophy. Another is the use of cross-functional RCM review groups of users and maintainers to apply the process. With careful training, such groups are able to use RCM2 to produce extraordinarily robust and cost-effective maintenance programs, even in situations where they have access to little or no historical data.

For a more comprehensive description of this formidable process, see John Moubray’s book “Reliability-Centred Maintenance”. To gain a better understanding of how RCM2 works, consider attending one of Sentratech’s RCM Training courses.

RCM Review Groups

The rigorous application of RCM2 completely transforms the view which any organization has of its physical assets. Not only does it revolutionize views about maintenance but it also leads to far broader and deeper understanding about how things work.

From the viewpoint of the business which operates the assets, these changes are both profound and profoundly important. The assets not only become more reliable because they are better maintained, but it also means that operators themselves are less likely to do things that cause their assets to fail. A better understanding of how systems work also means that operators are far more likely to react quickly, confidently and correctly when things do go wrong – a capability which is quite literally priceless, especially in complex, hazardous, tightly coupled facilities.

In nearly every case, it also transpires that people who live with the asset on a daily basis are an invaluable source of information – information which transforms what would otherwise be an occasionally valid collection of incomplete data into a solid, valid business tool.

This leads inevitably to the conclusion that from both viewpoints – technical validity and capability development – it is folly not to involve the people who live with the assets directly in the application of the RCM process.

The Aladon Network has developed a profound understanding of what must be done to ensure that RCM is correctly applied by such multi-disciplinary review groups.

However, before anyone can participate effectively in such a group, they need to learn RCM works (“learn the language”) and, more importantly, they need to come to terms with the Paradigm Shifts embodied in the RCM philosophy. Our RCM Training programs are designed to enable them to do so.