Page 31 - RCM - A practical Guide_V1

RCM - A Practical Guide

What effect does that then have on the parent?
We know what effect the failure mode has on the asset but what does that mean for the parent (asset
or system)?
This usually has a relationship with the functional failure itself. The physical and functional effect at
asset level, causes loss of function at the parent level.
Does it cause any secondary damage?
Are there any effects on other related systems or functions?
What does that mean to the platform?
The Platform or end item.
What does this mean to the overall equipment. Could it impact on safety? Could it result in
environmental damage? Do we completely lose availability or partially?
An example of an effect statement for our failure modes might be:
To stop the car within 100 metres on a dry surface and to achieve this at its gross vehicle
weight
a. Does not stop the car at all
b. Stops the car at a distance more than 100 metres
Why? - ABS ring corrodes

Oxidation, over time, leads to reduction in material thickness and
eventually, with repeated heat cycles, cracking. ABS ring unable to create a
smooth frequency. ABS reads frequency incorrectly and signals brakes to
release due to an apparent skid condition. Brake system unable to stop
within the specified distance. Vehicle unavailable during rectification.
Increased risk of damage and serious injury/death to the operator and
other road users.
c. Stops the car within 100 metres but at a weight less than gross

Other information
The FMEA, remember, exists to capture the information necessary to empower the analysis to answer
the questions in the RCM decision diagram. Having followed this process, we now know what the
system/asset is supposed to do, we know how it can fail to it and how that could be caused, and we
know what effect it will have.
But that is not necessarily quite enough information to answer the decision questions, we need yet
more information to enable us to answer correctly.
Detection method
How will the operator find out that the failure has occurred?
Things to consider:
• Obvious loss of function
• Abnormal system behaviour
• Routine operator checks/tests
• Warnings
• Obvious impending doom

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