Reliability Centered Maintenance (RCM) is a systematic approach for identifying preventative or scheduled maintenance tasks for an equipment end item and establishing necessary preventative (or scheduled) maintenance task intervals. It’s generally used to achieve improvements in fields such as the establishment of safe minimum levels of maintenance, changes to operating procedures and strategies, and the establishment of capital maintenance regimes and plans. Successful implementation of RCM will lead to an increase in cost-effectiveness, machine uptime, and a greater understanding of the level of risk that the organization is presently managing. The results of the analysis provide a clear decision as to which preventive maintenance tasks should be developed to support the system. Condition Based Maintenance Plus (CMB+) is maintenance performed based on evidence of need provided by RCM analysis. [1,2]
RCM is based on the following: 
- The objective of maintenance is to preserve an item’s function(s). RCM seeks to preserve a desired level of system or equipment functionality.
- The RCM process is a valuable life-cycle management tool and should be applied from design through disposal.
- RCM seeks to manage the consequences of failure, not to prevent all failures.
- RCM identifies the most technically appropriate and effective maintenance task and/or other logical actions
- RCM is driven by the following considerations, in order: safety (or a similarly critical consideration), the ability to complete the mission, and economic grounds.
- RCM acknowledges design limitations and the operational environment. At best, maintenance can sustain the inherent level of reliability within the operating context over the life of an item.
- RCM is a continuous process that requires sustainment throughout the life cycle. RCM uses design, operations, maintenance, logistics, and cost data, to improve operating capability, design, and maintenance.
A DoD-approved RCM process includes the following items in sequence:
- Functions: The desired capability of the system, how well it performs, and under what circumstances.
- Functional Failures: The failed state of the system (e.g., the system falls outside the desired performance parameters).
- Failure Modes: The specific condition causing a functional failure.
- Failure Effects: The description of what happens when each failure mode occurs, detailed enough to correctly evaluate the consequences of the failure.
- Failure Consequences: The description of how the loss of function matters (e.g., safety, environmental, mission, or economics).
- Maintenance Tasks and Intervals: The description of the applicable and effective tasks, if any, performed to predict, prevent, or find failures.
- Other Logical Actions: Including, but not limited to, run-to-failure, engineering redesigns, and changes or additions to operating procedures or technical manuals.
AcqLinks and References:
- Defense Acquisition Guidebook (DAG) – Chapter 5
- MIL-STD-2173 “Reliability Centered Maintenance” – 21 Jun 1986
- DoD CBM+ Guidebook – May 2008
- NASA Reliability Centered Maintenance (RCM) – Feb 2000
-  DoD Instruction 4151.22 “CMB+ for Materiel Maintenance” – 2 Dec 2007