Maintworld 3/2018

ReliABility
Takt time target, through a cross-functional team we analyzed
the specific manner of failure for each machine assembly associated
with our “Bad Actor” systems. One outcome of the
analysis was a set of common Failure Codes – a unique set of
codes that can be used to evaluate the frequency of problems
by asset class, failure class, or by specific causes – that were
then implemented in Maximo to evaluate the effectiveness of
engineered Equipment Maintenance Plans. A second outcome
was a ranked, prioritized list of consequence risks. Using a
traditional set of criteria to define the Risk Priority Number,
or RPN for each functional failure and failure mode, the team
was able to determine which functional failures represented
the greatest risk to Takt Time, the leading business objective
linked to our project, and the ranked order of failure codes
that specifically contribute to this elevated level of risk. In
short, if we began with 250 failure modes for a system, we prioritized
our way down to 12 likely, consequential failure modes
that have a direct, significant impact on Takt time. Twelve
failure modes that would be used to construct a new Equipment
Maintenance Plan, and 238 failure modes that would be
used to evaluate maintenance effectiveness, by way of Failure
Codes, and the effectiveness of standard operating procedures,
MRO strategies, and other asset management plans.
Full circle. Feeling good about the FMEA outcomes, and
relieved by the fact that we prioritized failure modes for reengineering
maintenance plans, I returned the team’s focus
back to Asset Criticality Analysis. We still needed to evaluate
and rank each manufacturing system in terms of the business,
and wanted to define the actions required by Engineering,
Maintenance, Operations and Procurement to mitigate business
risks. Admittedly, I was trying to check my box. A box on
my mental “RCM Checklist” that I had made and have used
for the past 17 years. A list that delivered confident results over
and over again. Excitedly, however, I learned a new lesson. The
items on the list, like the FMEA and Asset Criticality Analysis,
each answered a specific question, and each taught us something
new about our assets that we did not know without it.
But, it was just a list! It was not a sequence or process! It does
not matter where the list begins or ends! RCM is not intended
to be a repeatable process!
Asset criticality is based on the
understanding of how each asset,
maintainABle or not, functions within
the business to meet organizational
oBJectives.
Using the prioritized, ranked list of high-risk failure modes as
thke basis of evaluating the impact to the business, the team
and I launched off into asset criticality. System by system we
used the “predominant functional failure” and their unique set
of failure modes to qualify risk in terms of:
• Downtime impact to Production,
• Potential Impact to Personnel Safety,
• Potential Impact to the Environment, and
• Cost of Corrective Maintenance after one of our
unique failure modes occurs.
My next statement will likely cause some traditionalists to
erupt with emotion, shouting for all to hear that the team’s
analysis is corrupt based on the modal distribution of rankings.
But I am going to say it anyway. The Asset Criticality Analysis
results were eye-opening! 64 percent of the “Bad Actor”
systems analyzed, and their subsystems and major machine
assemblies, fell into a “Low Risk” profile. 12 percent, oddly
enough, landed squarely in the “High Risk” ranking profile –
Insufficient risk controls.
Insufficient risk controls.
Re-engineer asset or management
systems to eliminate failure modes.
Sufficient risk controls.
Monitor and trend asset health and
operating conditions.
Sufficient risk controls.
Look for opportunities to
optimize cost.
% High 12%
% Medium 24%
% Low 64%
What I learned in this odd sequence of reliability centred
maintenance is that the FMEA enabled us to look deeper into
the definition of risk, and normalize our collective assumptions
using real-world scenarios that provided relevant pain
for all parties involved in the analysis. Asset Criticality Analysis
was no longer a subjective exercise to confirm our suspicions
about what was “critical”. It had real meaning, and was
able to tell the team and I if our current risk controls were protecting
the Company’s investments or exposing it to unnecessary
risks. The analysis also helped the team recognize where
asset management plans could be optimized, saving time and
money, without impacting the current level of risk mitigation.
As I said, 64% of the assets analyzed fell into this ranking
profile. Seasoned practitioners may recognize this pattern as
the “over tinker” realm, in which production downtime and
maintenance costs are elevated because of excessive volumes
of time-based, fixed frequency, or even non-value adding preventive
maintenance.
If you are still not convinced, but are moderately intrigued,
let me tell you what we did next. I too was sceptical due to my
preconceived notions of how the RCM process was meant to
flow, and my cognitive bias of how a criticality analysis result
was supposed to look. Next, the team, with help from equipment
representatives, conducted a 9-part evaluation of the
condition of both the 12 percent “High Risk” and 64 percent
“Low Risk” assets. They peered over the physical health of
each major component, looking for obvious signs of neglect.
They scrutinized preventative maintenance procedures to
conclude whether each PM was effective as written and scheduled.
They dug into the availability of spare parts, including
recent stockout history and replenishment cycles. They even
examined maintenance training records as a possible indication
of Maintenance Quality and Defect Elimination. This
“Equipment Condition Assessment” was meant to prove or
disprove our findings from the Asset Criticality Analysis. Was,
in fact, the Company’s risk less for the 64% because they were
doing a better job of managing the known, FMEA identified
failure modes? The result was a resounding “YES”. Although
the numbers were not identical, and maybe a second article
will follow explaining why, 88 percent of the assets analyzed
were deemed “Maintainable” with the current controls. Five
percent on the other hand, were not maintainable and leaving
the Company exposed to unnecessary, preventable risks.
48 maintworld 3/2018