Reliability Centered Maintenance
What is reliability centered maintenance?
Reliability centered maintenance (RCM) is a process for determining the level of maintenance that’s needed for a company to operate effectively in terms of overall cost, production availability, spare parts stockholding, and other factors.
Reliability centered maintenance was a product of airline maintenance schedules which are among the most intensive of any industry. Airlines have to undergo extensive servicing for safety but these services must be balanced with the need for the airline to generate revenue and continue operating. Balancing these two elements are difficult as machinery (i.e. airplanes) becomes increasingly complex and has multiple possible failure modes.
Reliability centered maintenance requires more time up front but helps with this balancing act. It helps companies establish a maintenance plan that is both cost and equipment effective.
Evaluation criteria for RCM
The first step is to evaluate an individual asset’s purpose, failure modes, and business impact. Evaluation criteria for RCM processes is defined in the technical standard SAE JA1011.
The process begins with these seven questions:
- What is the item’s purpose (main action) and performance standards?
- What are ways it can fail to perform main action?
- What events are the cause of each failure?
- What happens when each failure occurs?
- How does each failure impact the system?
- What task can be performed proactively to prevent, or lessen the impact of, failure?
- What actions must be taken if a preventive task can’t be found?
Answering these questions will give you an idea of which components of RCM to implement for a particular asset. Components include reactive, preventive, predictive, and proactive maintenance (see chart below). One or more of these maintenance types may be implemented.
Components of an RCM program
Your company may have non-critical equipment that can receive reactive maintenance based on your RCM evaluation. This type of maintenance is good for low-impact assets with parts that can be replaced quickly when they fail. Conversely, you may have operation-critical equipment that runs continuously and has known failures. Based on this analysis, the RCM program would include preventive maintenance (PM).
Based on your evaluation, your assets may warrant more advanced maintenance types like predictive and proactive maintenance. These will require more time to implement up front but will increase safety, uptime, and cost-savings in the long term.
The difference between RCM and preventive maintenance
Preventive maintenance and reliability centered maintenance are often mistaken for being the same thing. While preventive maintenance has a number of advantages including increased equipment life, reduced energy usage, and less unexpected failures, it can run up maintenance costs when applied to every asset in a facility. Because PM isn’t selective like RCM, it can be very inefficient.
Reliability centered maintenance reduces inefficiencies by assigning unique maintenance activities to individual assets. Each asset is “put under the microscope” and carefully considered before a type of maintenance is assigned. In some cases, this may happen to be preventive maintenance.
You can use reliability centered maintenance to decrease maintenance costs while upholding compliance by applying the right types of maintenance to individual assets. Instead of applying a single maintenance type facility wide, you can use RCM to make maintenance more targeted, individualized, and efficient. This is a maintenance strategy that requires significant resources up front but has the ability to turn your maintenance program into a world class operation.