Reliability Centered Maintenance (RCM)

What is Reliability Centered Maintenance?

Reliability Centered Maintenance (RCM) is the process used to determine the maintenance strategy to be applied to increase the likelihood that your company’s assets function optimally over the design lifecycle in the most cost-effective manner.

The outcome of the RCM is the implementation of any of Preventive Maintenance (PM), Predictive Maintenance (PdM), Run-to-Failure (reactive maintenance) and Proactive Maintenance strategies on each of your company’s assets.

Overall, the objective of RCM is to ensure that your company’s maintenance program achieves high levels of operational readiness, safety, environmental soundness, and reliability at low cost.

These core principles guide the RCM process:

  • RCM focuses on systems – it is about maintaining high levels of system function
  • RCM identifies and seeks to preserve equipment functions that can affect the system function.
  • RCM focuses on asset design limitations. It is interested in managing an assets’ likelihood of failure at specific ages given that maintenance can only sustain operational equipment to its design-based level of reliability.
  • RCM minimizes the consequence of asset failures. It identifies, prioritizes, and select appropriate and effective task controls to prevent and manage asset failure.  
  • RCM prioritizes safety at any cost; then cost-effectively.
  • RCM is an ongoing process of screening maintenances tasks to provide a consistent approach to maintain all kinds of assets

     

RCM Maintenance Tasks

The outcome of an RCM is three maintenance tasks:

Preventive Maintenance (PM): this is time-dependent maintenance activity carried out when appropriate, to prevent an asset failure.

Predictive Maintenance (PdM) and Real-time Monitoring: these are condition-dependent strategies performed when preset or real-time asset condition demands.

Proactive Maintenance and Run-to-failure Maintenance: these maintenance tasks focus on failure finding after the asset is allowed to run-to-failure as suitable for some assets, under certain conditions.  

Critical questions for RCM analysis

The reliability centered maintenance considers the reliability of assets in a facility based on the answers to the following critical questions:

  • What are the performance indicators of the assets?
  • What are the functions of the system each asset is part of?
  • What functional failures are likely to occur and what are the possible causes?
  • What are the likely consequences of these functional failures?
  • What can be done to reduce the probability of the failure, identify the onset of failure, or reduce the consequences of the failure?
  • What should be done if an appropriate preventive or proactive maintenance task cannot be determined?

Why RCM

Reliability-centered maintenance facilitates your company’s capabilities to minimize system failures, increase asset reliability and availability to meet set KPIs. It prioritizes assets that are most likely to fail, fails frequently, or with a devastating consequence of failure.  Then subject such assets to cost-effective maintenance tasks that cut down the likelihood of failure.

By implication, RCM reduces maintenance cost and increase asset uptime.

However, RCM is disadvantaged when the process fails to consider the cost of acquiring and maintaining an asset.

How to implement Reliability Centered Maintenance (RCM)

The various approaches to RCM have the following vital steps in common:

  1. Select critical assets for RCM analysis: critical assets are those assets that have the most impact of your company’s operations in the event of a failure, The effect could be regarding the cost of repair, cost of preventive maintenance, or the extent of the consequence of failure.
  2. Specify the functions of the system to which the assets selected belongs: each asset is part of a system that performs a crucial function. Define the role of the system with the inputs and outputs.
  3. List all the ways the function of the system can fail.
  4. Identify the likely causes of the expected system failures. With the help of your team of experts: technicians, operators, you can determine the ways the functions of a system can fail and the root causes.
  5. Specify the consequence of each asset’s failure and determine the most critical. From operational shutdown to safety and cost implications, you can learn the result of each asset failing systemically through:
  • Risk-based inspection (RBI)
  • Failure, mode and effects analysis (FMEA)
  • Failure, mode, effect, and criticality analysis
  • Hazard and operability studies (HAZOPS)
  • Fault tree analysis (FTA)
  1. Choose the most appropriate RCM maintenance tasks to manage the failure of each asset efficiently and cost-effectively.  
  2. Implement and then regularly review the RCM maintenance tasks selected. Because RCM is a continuous process, it is crucial that you consider the resulting maintenance tasks regularly and renew as you find additional information.