Page 32 - RCM - A practical Guide_V1

RCM - A Practical Guide

In all cases, the information should be detailed enough to lead a reader to the same conclusions that
the analysis has arrived at (without directing them with buzz words like ‘obvious’, ‘evident’, ‘hidden’.
Compensating provisions
When the failure occurs, there may be something that happens or that an operator can do to stop the
situation deteriorating or restore some form of functionality.
These are called Compensating Provisions or Mitigating Actions. It’s important to remember here that
we’re looking for mitigation of the effects of failure and not necessarily the failure itself.
They may include (but not limited to):
System design features:
• safety or relief devices
• monitoring or alarm provisions which allow effective operation or limit damage
• alternative modes of operation such as backup or standby items or systems
Operator actions:
• resetting circuit breakers
• manually selecting a backup device
• manually shutting down the system etc
• failure isolation
Compensating provisions are important. The FMEA is written as though the failure mode is allowed to
run its course, it is done like that in order not to cloud the thinking but, when it comes (later on) to
decide whether or not to introduce a maintenance penalty, it’s important to recognize when
something is already mitigated.
A failure effect may read like a catastrophic event but if there is something inherent that prevents that
effect happening then you’re probably not going to try to mitigate it.
Financial impact
If one of your arguments for introducing maintenance is going to be based on the financial impact of
failure then it may be prudent to capture information here.
Considerations could include:
• Mean time to repair (MTTR)
• Mean active repair time (MART)
• cost of:
• spares
• manpower
• lost operations

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