Thank you for that clarification Daniel, would you mind sharing the white paper?
I agree that ISO14224's codes in tables B6 to B14 which is called "Failure Modes" are rather "Problems" or "Symptoms" that were observed, and is descriptive of the Function that was lost (RCM Question#1), it does not describe the "technical cause". In ISO the Failure Mechanism describes the "technical cause" - see context under B2.2
In order to arrive at a sufficient Failure Mode as per Boubray's definition, the other ISO data elements of Failed Sub-Unit/Maintainable Item; and Failure Mechanism need to be added to the Observed Problem for a full failure mode.
As an example, the following failure mode
"The pump produced low pressure due to degradation of the impeller" is made up from the following structured data elements:
- Equipment = Pump (e.g. P-1234)
- Observed Problem = Low Output (Table B5 LOO)
- Failed Maintainable Item = Impeller (Table A21)
- Failure Mechanism = Wear (Table B2 2.4)
- Number 1 and 2 must be recorded when an operator requests work to be done.
- Number 3 and 4 must be recorded when a maintainer completes the repair or investigation.
With these 4 data elements, criticality (RCM Q2) and the MTBF, a Maintenance Plan can be established or improved to prevent/mitigate re-occurrences (RCM Q6)
All possible combinations of these 4 data elements results in an extremely large list of RCM failure modes, I am of the opinion that it is better and easier to manage individual value lists for each data element, and then analyze how many times they are recorded in combinations to target the relevant failure modes in the maintenance plan.
On a similar note - ISO14224's table B3 "Failure Cause" does not describe technical causes, it describes the underlying cause (including human cause), which does not provide information with regards to the maintenance plan for a specific equipment, it provides information related to failure of the overarching management of M&R (which would include competence, training, documentation, process, strategy, design, etc.) The only possible technical cause in B3 is 3.4 "Expected Wear and Tear" which might be seen as out of place and redundant to the same code in Failure Mechanism.
Does this make sense? Please let me know thoughts from others.
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Philip Schachtner
Cenovus
Calgary AB
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Original Message:
Sent: 08-21-2019 11:53 AM
From: Daniel Ortiz
Subject: Failure Modes in CMMS
Hi everybody. Please, take into account that failure mode had a different definition, basically, between RCM (SAE, IEC, Moubray, etc.) and ISO 14224 (2006) or OREDA. RCM describe (my opinion) it better than ISO (old version). If you see all examples in ISO or OREDA, they represent failures o symptoms, not an "event than cause the failure" (RCM definition for failure mode). Last version of ISO 14224 change its failure mode definition, to make the same as IEC60300-3-11, but didn't change the tables. My recommendation is to include in CMMS the RCM's failure mode data (if you have developed a RCM), this will permit to evaluate your plan and correct it if proactive task for each failure mode was not OK and improve it. If you wish, I could share a white paper to explain this situation. Regards
DANIEL ORTIZ PLATA
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[Daneil] [Ortiz Plata] [CMRP]
[Mechanical Engineer]
[Ortiz Ruis Consultores]
[Bogotá] [Colombia]
Original Message:
Sent: 07-29-2019 10:19 AM
From: Greg Mecomber
Subject: Failure Modes in CMMS
I'm trying to implement a change that would include asset specific functional failures (at least) and failure modes into our E-Maint CMMS.
What I had in mind doesn't seem to be as easy as I thought it would be. Can anyone offer any suggestions or screen shots as an example for how you have successfully utilized failure modes in your CMMS reporting?
Thank you!
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Greg Mecomber
Smile Direct Club
Maintenance & Reliability Engineer
Nashville, TN
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