MANAGEMENT
There was a book written in 1978 that transformed
34 Fleet Maintenance | May 2018
maintenance. It was called “Reliability-
Centered Maintenance” (now known as RCM)
by F. Stanley Nowland and Howard H. Heap.
Both worked for United Airlines – Nowland as
the director of maintenance analysis, and Heap
as manager of maintenance program planning
– conducting a study and providing a subsequent
report on airline maintenance practices.
Sponsored by the Offi ce of the Assistant
Secretary of Defense, the results of the study
were printed as a book in order to share
insights with other disciplines, such as the U.S.
military, on scheduled-maintenance programs.
Th is work was the result of the techniques
used to design and maintain aircraft . Th e fi rst
jet that used RCM was the Boeing 747 (which
originally rolled off the line in 1969). Th e 747
was more reliable and needed less maintenance
then the prior generation Boeing 707,
and was quite a bit bigger and more complex.
Addressing random failures
Th e notable thing about this study, among
others, was when they looked at failures they
found that most of them were not caused
by wear and tear, or age. Most failures were
random. An example of a random failure might
be when a vehicle is driving down the road and
a rock cracks or breaks the windshield.
No amount of preventative maintenance
(PM) would help to anticipate or mitigate that
kind of failure. Other random events like road
hazard tire failures, gunk in the diesel, (some)
brake failures and (a few) transmission failures
can be somewhat managed, but not eliminated,
by good PM service.
Th eir study found that more than 75 percent
of the failures were random in nature. Th e problem
with this is that the focus of a PM program
seems to manage only a small percentage of
potential failures. Th e same holds true for
commercial vehicle fl eets.
Th ey grappled with how you manage these
random failures. Th ink about it: an aircraft
fl ying at 36,000’ with 200 souls on board. Th e
consequences of a failure were even more critical.
So how did Nowland and Heap help to
address this issue?
Defense in depth
Th ey decided to look fi rst at the consequences
of a breakdown (broken into categories such as
fatalities, environmental catastrophes, airplane
downtime and cost of repairs, etc.) to see if it
was worth it spending the time to reduce the
chance of failure to as close to zero as possible.
Th e solution was known as “defense in depth.”
Defense in depth is a concept that is used in
mission-critical applications to address how
you manage your eff orts. It starts with a failure
mode.
For example, let’s say loss of engine power
is the failure mode. What are the items that
could cause this loss of power? Some are typical
maintenance issues such as bearing failure, a
crank breaking, a clog in the fuel line, a broken
cam shaft , etc.
However, many causes to the loss of power
may not be maintenance-related at all, like a
bird strike, running out of fuel, bad fuel, pilot/
driver reducing the throttle, etc.
Defense in depth considers the causes and
seeks to eliminate all of them. Th is makes the
vehicle system (truck, airplane, submarine)
more robust.
First, for fl eets, it means looking at the consequences
of diff erent failures.
Secondly, it means applying all the tools and
resources available to the fl eet to help eliminate
or reduce the chance of the critical non-maintenance
related occurrences from happening.
Tools can include, but are not limited to,
reengineering, refi ning pre-trip checklists,
changes to training, enrolling the driver in
run-time inspection, fi nding new aft ermarket
products, adopting new procedures, ensuring
procedures are followed and many more.
All of this will be aided by specifi c discussions
with all the participants (technicians,
drivers, washers, fuelers, parts room people,
etc). PM alone will never get you there.
How do you manage
random vehicle failures?
It’s not just about
optimizing PM; personnel
communication is critical.
» “Reliability-Centered Maintenance” (RCM)
looks at the consequences of different failures
to reduce or eliminate the chance of critical
non-maintenance related occurrences.
Photo from iStock
Defense in depth
identifies all causes of
breakdown and seeks
to eliminate them.
By Joel Levitt
PRESIDENT, SPRINGFIELD RESOURCES
Springfield Resources (maintenancetraining.com) is a
management consulting firm that services a variety of
clients on a wide range of maintenance issues. Levitt is
the president of the company, and has trained more than
17,000 maintenance leaders from more than 3,000 organizations
in 24 countries. He is also the creator of Laser-
Focused Training, a flexible training program that provides
specific targeted training on your schedule, online to one
to 250 people in maintenance management, asset management
and reliability.
/maintenancetraining.com
