Oil Analysis in Reliability Centered Maintenance
by Micheal Blackmon, CLS
Business Development/Reliability Specialist

Reliability Centered Maintenance (RCM) methodology is the process that is used to determine the most effective approach to maintenance. It involves all of the maintenance strategies and identifies the most cost effective actions that will reduce the probability of failure.

There will be an ideal mix of condition-based actions, time-based actions, and run-to-failure approach. The RCM process identifies all asset’s functions and functional failure along with all reasonably likely failure modes and their causes. From here, the effects of these failure modes are identified and how these effects matter. With this, the RCM process determines the best asset management strategy. There are essentially seven steps in the RCM methodology:

  1. Function – What is the function of the asset?
  2. Functional Failures – In what ways can this asset fail to fulfill its functions?
  3. Failure Modes – Exactly what causes each functional failure?
  4. Failure Effects – What happens when a failure occurs?
  5. Failure Consequences – In what way does the failure matter? The failure modes will fall into one of four categories of consequences: hidden, evident safety or environmental, evident operational, and evident non-operational.
  6. Proactive Tasks – What should be done to predict or prevent each failure? There are three types of proactive tasks to consider: on-condition or predictive tasks, scheduled discard tasks, and scheduled restoration tasks. Scheduled discard and restoration tasks are considered preventative tasks.
  7. Default Actions – What if there is no suitable proactive task? Should the asset run to failure, or should changes be made in the design or process?

Oil analysis plays a key role in developing a successful RCM program and can be broken into three categories: Fluid Condition Analysis (FCA), Contamination Analysis (CA) and Wear Debris Analysis (WDA). FCA and CA are proactive programs that determines the condition of lubricants in operation and contamination that may be present. Preventative tasks, such as oil change intervals or contamination removal, may be scheduled based on oil analysis history. The other aspect of tribology analysis is WDA, which would include spectroscopy, ferrography, particle quantifier index, and laser net fines. Unique wear patterns found in the lubricating oil can provide a means for isolating failure modes. WDA can also be used as a failure analysis tool to help understand the root cause of catastrophic failure. Understanding wear patterns and failures can help improve the RCM process.

Once the RCM methodology has been established, the tasks within should be evaluated using leading key performance indicators (KPIs) to measure how well the tasks are being conducted. The results from oil analysis will provide input into and affect many of the KPIs in the reliability process. The flowchart below shows how oil analysis plays a role in the RCM methodology.

While oil analysis is only a small part of the RCM process, it can be a valuable tool that helps establish other tasks within the RCM methodology. A well-managed oil analysis program can provide substantial returns and is a must in a comprehensive RCM program. Contact one of ALS Tribology’s Reliability Experts today to help transition your oil analysis program into a successful RCM program.