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System of Systems
Why the Smallest Link in the Smallest
Operating System is Important
The management of maintenance is different from managing every other task in
a company. Unfortunately, because of many reasons, the technical skills required
to understand the gravity of this has been lost from all our sources of
education. High schools have abandoned the traditional shop and electronics
classes. The business schools in our colleges have totally abandoned any
attempts to incorporate the management of maintenance into their business
degrees and the engineering schools have become swamped with technical details
and have moved any discussion concerning maintenance to the nothing more than
cursory touching of the subject. The whole subject of managing maintenance
by an executive has been left to OJT (On the job training) when they accept the
reins of a company.
It seems that the only people who really understand the company-wide effects
of deferring maintenance are those in the Maintenance Department and for many
reasons their input is not accepted as valid. This paper is offered to help
explain why attempting to reduce maintenance spending to reduce maintenance
costs actually triggers an exponential explosion in maintenance spending.
The single biggest challenge in managing maintenance is to assure full
funding to meet the minimum needs of the machines when the machines are
available to be serviced. Knowing the "minimum needs of the machines" is where
the person who manages the maintenance manager applies the consequences of all
of other business functions to managing maintenance and small errors are set
into motion that will amplify over time to become large enough to endanger the
operational functions of the company.
For the sake of brevity, I will offer an event that happened to me when I was
an aviator in the Marines. I was the fourth pilot in a four plane mission but
only three aircraft were up and ready. It began to look like the mission was
going to have to launch without me so I started hinting to the Maintenance
Controller that I would be willing to take a jet that was less than fully
mission capable.
The Maintenance Controller took me outside and put a small wrench in my hand
and said, "Captain, pretend that is your pistol and shoot a hole anywhere in
that airplane that you would still be willing to fly it."
Well, I knew the plane well enough to know that every cubic inch under that
aluminum skin had something important in it. Something that if missing might let
the jet fly but not perform its mission.
"Ok, I get it." I said but Ellis Crews wasn't through with me yet.
"For Douglas to win the contract to build this airplane they
had to have the lowest bid. If they put anything in the plane that wasn't
requested by the government it would cost them the contract so they didn't put anything inside
that skin that wasn't needed." and Ellis walked away.
At that moment I understood the concept of a system of systems. The jet
fighter was a
system of smaller systems and each subsystem was a system of components. If any
system failed, the aircraft could not perform its mission.
Today, during budget planning sessions, budget managers tend to believe that
the systems that have to be maintained have subsystems that are either redundant
or excessive and that these systems can be ignored. This is not true. Redundancy
is not provided with the lowest bid.
When a purchasing agent goes out for bid to meet a need for a machine they
give a description of the capabilities of the machine to the vendor and will not
pay for "gold plating" or "extra capability" that is beyond the specification
for the job the machine has to perform.
When the vendor answers the RFQ (Request for Quote) they offer a machine that
will perform to the specifications. To offer more will cause them to be other
than the low bid.
Therefore, the machine purchased by the purchasing agent will be one with
only those parts necessary to perform the specified tasks. It will be the low
bid.
So, if it is a machine is purchased with only the necessary parts to perform the
specified tasks,
which parts do not need to be maintained? The answer is that all the parts have
to be maintained or the machine will not perform to specification.
I am going to offer an example of one subsystem and examine the components.
Let us use the hydraulic system for a top-drive on an oil well drilling rig.
Imagine standing next to an operating rig and pretend that
you have a high powered laser gun. What part could you burn off this top-drive
and it would continue to run as needed? let us examine the hydraulic system.
Every component within this drilling rig subsystem is
necessary for the function of the top-drive unit. It cannot function
properly without every component. When this drive was ordered there were no extra
components installed. Each of these components must be maintained.
Fluid Filters - The hydraulic fluid cylinders must be
maintained so that the fluid will be clean, flow properly, and not foul the
internal mechanical systems. The fluid must be clean. Dirty fluid will
destroy the pumps, cylinders and controls. Hydraulic Fluid
- The fluid has three key requirements. It must lubricate the internal
mechanical components as they operate.
The hydraulic fluid must carry away heat generated in the
transfer of fluid power.
And, it must be maintained in such a condition that it cannot be compressed.
Any air or other gases that contaminate the hydraulic fluid during
circulation creates shockwaves that feedback to all the key components and
can destroy them.
Hydraulic Fluid Tank - The levels must be full as per
the design specifications of the fluid will not have time to dissipate the heat carried
away from the pumps, cylinders, and motors by the fluid.
Heat kills. If the oil level is low, the heat will be retained and carried back to the
components. The temperatures will rise and the components will fail before
their time.
Hydraulic Pump - This is the heart of the hydraulic system. It creates
the high pressure that does the work. It has seals to change rotating energy
into hydraulic pressure. If these seals leak, pressure is lost and less work
can be done. Maintaining the integrity of the entire system protects it from
heat, contamination, and resistance to flow.
Piping - The outside of the piping must be kept clean so that heat
can be dissipated. The piping must be kept intact so that fluid will not be
lost. The piping must not be dented so as to increase the resistance to flow
and create heat and higher working pressures for the pump. Piping must be
protected from water moisture in the lines to prevent internal rusting in carbon steel lines, steel pump housings, and motors.
Controls - The valves and orifices in the control units will stick or
fail prematurely if the fluid and filters are not serviced properly. The
only thing that is more exciting than a hydraulic motor that won't turn is
one that won't stop turning. Control units fail because of rust, corrosion,
and contaminated fluid. Accumulator - These devices
absorb the shock of rebounding pressure waves within the hydraulic system.
The energy is absorbed through a charged cavity
(Usually with nitrogen.) that is open to the hydraulic system pressure. As operators bang the controls,
pressure waves rebound off the closed valves and batter the internal
components unless they are absorbed in the accumulator. Keeping the charge
pressure at the correct value is an essential maintenance function. Cylinders and
Motors - This is where work is done and wealth is created for the investor. Moving hydraulic cylinders position components and the
rotating hydraulic motors crunch through rock. Any contamination that
reaches these devices can create a loss of fluid and a loss of pressure.
This slows down or stops the job. Each and every one of these
components must function together to create wealth for the investor. There are no
gold-plated components here. There are no components that can be ignored
here. The least expensive component must be maintained with as much
commitment as the most expensive component. They must all be maintained.
There is no other option than will produce a lower maintenance cost per unit
of production. These components cannot be motivated by human standards. No
amount of pep talks or pleading will keep a filter from bypassing and
dumping contaminates into the drilling motor if it is blocked. It takes man-hours, materials,
and money to sustain these machines in the creation of wealth.
At budget time, you must remember this:
Maintenance only replaced that part
of the
machine that was consumed during the
creation of wealth for the
investor.
If you restore the wealth producing components, more wealth can be
created at the same rate as before. If you do not maintain the wealth
creating components, the amount of wealth you can create in the future will
be diminished or stop. If you should care to visit concerning the
points of this white paper, I am at your service.
Sincerely, David Geaslin
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