Reliability Centered Maintenance

What is Reliability Centered Maintenance?

Reliability Centered Maintenance (RCM) is a customized maintenance process determined through the analysis of potential failure modes and their impact on system performance.

Pioneered by the airline industry, reliability-centered maintenance encompasses reactive, preventive maintenance programs, and predictive (condition-based) maintenance as well as failure-finding processes to detect hidden or latent failure modes. By studying cause and effect relationships along with the probability and outcome of each failure, maintenance tasks can be cost-effectively prioritized based on safety, security, and the importance of each asset to the overall operation.

Reliability Centered Maintenance Principles

While root cause analysis uses cause and effect relationships to examine why a given failure occurred, RCM maintenance principles are based on understanding what is likely to happen if the cause of failure is present. The core premise is to preserve system functionality by determining what the potential failure modes are and then exploring and weighing the causes and consequences of each one. This makes it easier to prioritize and categorize failures and assign maintenance tasks to address them appropriately. RCM defines failure as any unsatisfactory condition from a slight degradation in performance to total loss of function.


RCM takes a holistic approach with equipment and system operation taking precedence over individual component functions. Actuary principles to balance risk factors such as age and usage against maintenance costs are also employed to avoid assigning costly protocols to low-value assets.


Reliability centered maintenance principles dictate safety and security must be ensured above all else. Once these two essential requirements are met, cost-benefit strategies can then be used to reduce discretionary maintenance expenses.

Reliability centered maintenance principles also acknowledge design limitations by recognizing feedback provided through maintenance history and using it to improve the design and predict asset lifecycles. Using logic trees to screen maintenance tasks consistently for all types of equipment, RCM requires a consistent focus on the applicability of maintenance tasks to failure modes, and the effectiveness of these tasks in cost-effectively reducing failure probability.

Reliability Centered Maintenance Advantages

Successful implementation of RCM can lead to improved overall cost performance, reduced downtime, and greater insight into the overall risk profile of the organization. By implementing a consistent, structured method to decide whether predictive, preventive, or run-to-failure strategies should be used, reliability centered maintenance can take the guesswork and debate out of these important decisions. With a high-level organizational perspective, often wasteful “cookie-cutter” type maintenance practices can be avoided.


Reliability centered maintenance principles can also be used to extend equipment life by basing replacement decisions on equipment condition rather than predetermined lifecycles. As more failures are prevented, operational expenditures will benefit from reduced repairs, overhauls and downtime. Safety and security are the paramount considerations of RCM, so property and/or environmental damage is avoided while employee engagement and satisfaction are improved.

Reliability centered maintenance is potentially the most efficient overall maintenance strategy because more complex maintenance processes are only applied when a strategic cost benefit has been established. At the same time, lower-value maintenance activities can be identified and eliminated in favor of appropriately scaled run-to-failure or more limited scheduled maintenance approaches.

Reliability Centered Maintenance Disadvantages

Although the advantages of reliability centered maintenance are apparent, it is not without some drawbacks. The initial costs associated with RCM implementation can be higher than other maintenance processes with equipment and training contributing to the total. There is also a significant investment in time and resources to complete the RCM analysis necessary to assign maintenance priorities. The potential savings will significantly outweigh these initial costs but deploying the system in full can take some time, so a little patience may be needed to fully realize the financial benefits.

Since RCM maintenance incorporates reactive, proactive, preventive maintenance programs, and predictive maintenance strategies simultaneously, other potential disadvantages are inherent to the approach selected. For example, if run to failure is chosen as the appropriate maintenance practice for an aging or seldom-used machine, the cost of maintenance will be low, but the risk and expense of an unplanned failure will be much higher than in instances where predictive or preventive maintenance programs are selected.


Failure Mode and Effects Analysis (FMEA) is a commonly used risk analysis tool for product and process development. Originated by the U.S. military in the 1940s, FMEA uses a quantitative approach to classify failure modes based on the severity of consequences, the probability of occurrence, and the ease of detection. These three factors are multiplied to generate a risk priority number (RPN) for each failure mode. This RPN provides a convenient and consistent method to comparatively evaluate risk and decide what type of mitigation path is needed in each instance.

Similar to FMEA, the reliability centered maintenance process also uses structured, standardized decision making to analyze the potential causes and effects of failure but is used exclusively for equipment maintenance analysis. Specific failures are described in much greater detail during the RCM process as compared to a typical FMEA. Mitigations are also more detailed in an RCM analysis because they will form the basis of very detailed maintenance plans and activities for years to come. Equipment performance standards, production output goals, and spare parts availability are other essential considerations of RCM analysis that would not be included in an FMEA.

Reliability Centered Maintenance Process

Before the reliability centered maintenance analysis can be performed and the optimized maintenance strategy implemented, some prerequisite steps should be completed. Planning activities include assigning RCM implementation leaders, selecting and training the team(s), studying equipment documentation and maintenance history records, and creating RCM maintenance team ground rules.


This sets the stage for selecting equipment to be analyzed, separating the “vital few” from the “trivial many”. Some important considerations include the value of the equipment to the overall operation, safety considerations, and the cost of unplanned failures in repair expenses and lost revenue.


Completion of each subsequent RCM analysis leads to a new set of activities, procedural updates, and training to implement new RCM maintenance practices. Depending on the outcome, it could also include maintenance data analysis adjustments, predictive maintenance sensor deployment, or equipment design changes to reduce failure probability.


As an iterative process, teams will continue to work through selection, analysis, and implementation stages repeatedly as the reliability centered maintenance process gains traction. Versatile and powerful software tools can be an important ingredient throughout the RCM lifecycle.

Reliability Centered Maintenance Tools

Reliability centered maintenance principles introduce a higher level of customization and versatility to the maintenance process which can also add complexity. Traditional reliability tools like FMEA and fault tree analysis provide the RMS process with models for logic and consistency. Wireless sensors, thermal imaging cameras, and other high-tech hardware tools also support RCM implementation by collecting the data that is continuously fed back and applied.


The traditional tools that enable a successful RCM maintenance deployment are supported and enhanced by MicroMain’s CMMS software solutions. Our CMMS can bridge the gap between RCM complexity and stress-free implementation by automatically generating alerts and work orders based on tailored maintenance plans and providing a centralized platform for maintenance data analysis and asset management. Tracking and reporting functions can be used to assess KPI performance and offer valuable historical data into the reliability-centered maintenance continuous improvement loop.