IEEE Spectrum April, 2008 - 36

mechanical engineering at the University
of Maryland, College Park, and a member
of the university's Center for Advanced
Life Cycle Engineering, I have been
developing tools to forecast and resolve
obsolescence problems. To deal with
that growing pile of unavailable supplies,
engineers in charge of long-lasting systems must basically predict the future-
they must learn to plan well in advance,
and more carefully than ever before, for
the day their equipment will start to fail.

he systems hit hardest by obsolescence are the ones that must perform nearly flawlessly. Technologies
for mass transit, medicine, the military, airtraffic control, and power-grid management,
to name a few, require long design and testing cycles, so they cannot go into operation

cAll it the dArk side of moore's lAw:
poor plANNiNg cAuses compANies
to speNd progressively more
to deAl with AgiNg systems
18 months. This dynamic hurts designers
with long lead times on products with
even longer field lives, introducing materials, components, and processes that are
incompatible with older ones.
The defining characteristic of an
obsolete system is that its design must
be changed or updated merely to keep
the system in use. Qinetiq Technology
Extension Corp., in Norco, Calif., a company that provides obsolescence-related
resources, estimates that approximately
3 percent of the global pool of electronic
components becomes obsolete each
month. PCNAlert, a commercial service
that disseminates notices from manufacturers that are about to discontinue
or alter a product, reports receiving
about 50 discontinuance alerts a day. In
my capacity as an associate professor of

grizzled
veterans
Major Military systeMs often last
40 to 90 years. During those lifetimes,
models are updated and systems retrofitted. But many newer versions still use
the same electronic subsystems as the
originals. shown here are the start of
development and the projected end of
support for each program.

soon after they are conceived. Because they
are so costly, they can return the investment only if they are allowed to operate for
a long time, often 20 years or more. Indeed,
by 2020, the U.S. Air Force projects that
the average age of its aircraft will exceed
30 years-although some of the electronics
will no doubt have been replaced by then.
Some of the best examples of obsolescence come from the U.S. military, because
it has been managing long-cycle technology programs longer than just about any
other organization in the world. But there
are also commercial aircraft that fall into
the same, almost incredible age range of
40 to 90 years. The Boeing 737 was introduced in 1965 and the 747 in 1969; neither
is expected to retire anytime soon.
When those systems were first built,
the problem of obsolete electronics was

B-52

1946
94+ Years Start:
Phaseout: 2040

NA * iEEE SpEctrum * April 2008

only vaguely addressed, if at all, because
the military still ruled the electronics
market, and the integrated circuits they
needed remained available for much longer than they do now. In the 1960s, the
expected market availability for chips
was between 20 and 25 years; now it's
between two and five. Call it the dark side
of Moore's Law, which states that the number of transistors on a chip doubles every
18 to 20 months: poor planning for parts
obsolescence causes companies and militaries to spend progressively more to deal
with the effects of aging systems-which
leaves even less money for new investment,
in effect creating a downward spiral of
maintenance costs and delayed upgrades.
The situation is a lot like owning a
car, which sooner or later begins to show
its wear. First the brakes may need to
be replaced, say, for $1000. Then it's the
transmission-$2000. Pretty soon you
start wishing you'd just bought a new car,
except that the money you've sunk into
maintaining the old car makes it likely
that you won't be able to afford a new one.
The Defense Department spends an
estimated $10 billion a year managing
and mitigating electronic-part obsolescence. In some cases, obsolescence can
trigger the premature overhaul of a system. The F-16 program, for example, spent
$500 million to redesign an obsolete radar.
In the commercial world, telecommunications companies spend lots of money
managing obsolescence in infrastructure
products, such as emergency-response
telephone systems. One way to deal with
it is to replace a failed device with a wholly
redesigned one; another is to stockpile
warehouses full of parts to cover the projected lifetime of a system. Both options
cost money that might have otherwise
been spent on expanding the business.
Obsolescence also isn't limited to
hardware. Obsolete software can be just
as problematic, and frequently the two go
hand in hand. For example, an obsoles-

aim-9

1953
72+ Years Start:
Phaseout: 2025

Kc-135

1954
63+ Years Start:
Phaseout: 2017

www.spectrum.ieee.org

from left: U.S. Air forCe; BoB SimonS/U.S. Air forCe; SUzAnne DAy/U.S. Air forCe

shortages-is a huge problem for designers
who build systems that must last longer
than the next cycle of technology. For
instance, by the time the U.S. Navy began
installing a new sonar system in surface
ships in 2002, more than 70 percent of the
system's electronic parts were no longer
being made. And it's not just the military:
commercial airplanes, communications
systems, and amusement-park rides must
all be designed around this problem, or
the failure of one obsolete electronic part
can easily balloon into a much larger
system failure.
The crux is that semiconductor manufacturers mainly answer the needs of the
consumer electronics industry, whose
products are rarely supported for more
than four years. Dell lists notebook
computer models in its catalog for about

http://www.spectrum.ieee.org

Table of Contents for the Digital Edition of IEEE Spectrum April, 2008