Efficient Plant November 2017 - 44

Answers to questions
facing today's reliability
& maintenance
professionals

department | on the floor

A PMO Will
Generate
Resources
Dr. Klaus M. Blache
Univ. of Tennessee Reliability
& Maintainability Center

HEN IT COMES to plant
operations, personnel regularly contend with scores
of issues. This month's Q&A focuses on
one of the issues raised in last month's
discussion.

How do I acquire the resources needed to support a
predictive/condition-based maintenance effort?

Maintenance Percentage Target
vs. North American Top Quartile
80
70

Percentage

60
50
40
30
20
10
0
Target
Actual

Reactive

Predictive

Preventive

| EFFICIENTPLANTMAG.COM

Start by doing a PM Optimization
(PMO). That means cleansing
your maintenance tasks. A PMO
process is a structured methodology
that makes sure your technician/trade
functions are adding value. It means
throwing out, changing, and adding
tasks.
Use an FMEA (Failure Mode and
Effect Analysis) approach to understand
the frequency, severity, and detectability
of failure modes and potential impact
on equipment function. Meet regularly
with operations, maintenance, and
engineering personnel to separate the
actions, facts, and general information.
Then, evaluate how well the action
tasks will protect the machinery and
equipment functions against potential
failure modes.
One way to do this involves asking
several sequential questions to enable
the most desirable type of maintenance.
This identifies/improves ineffective
maintenance tasks. Ideally, you want all
maintenance tasks to be cost effective. If
you can't eliminate the task, implement

the highest level maintenance type
possible, starting with condition-based
functions to trigger maintenance events.
If that's not possible, then implement
measured factual tasks, then subjective
(observed without measurement), then
time-based, and finally, reactive tasks.
Condition-based maintenance is
always better, because it's less expensive,
non-intrusive, less labor intensive, and
uses the full life of the component. Also,
if the P-F (Potential-Failure) interval
is short, then condition monitoring
or eliminating the failure mode is
most likely required. Use your current
maintenance tasks, failure history, any
additional details in the computerized
maintenance management system, and
employee experiences. Basically, do
something.
You need to be doing at least 35%
predictive maintenance (finding issues)
to be at best practice and 25% for top
quartile. This doesn't include corrective
work, i.e., fixing what you find. That's
counted as preventive. Figure 1 shows
that the difference between where you
should be (target) and the North America actual top quartile is not significant.
I published the targets prior to 2009,
based on an earlier study. The actual
data is from a 2016 study based on 140
companies (representing about 3,000
facilities).
Make sure that the final PM tasks are
clear, specific, and can be performed by
technicians/trades/operators who have
been trained and are following their
standardized work. Overall, PMO helps

Research data show that meeting standard target maintenance-type percentages puts your
operation in range of top-quartile plants. Source: Univ. of Tennessee R&M Center, Knoxville

NOVEMBER 2017

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Table of Contents for the Digital Edition of Efficient Plant November 2017