Photo: NASA Electronic Parts and Packaging Program

Sneaky Splinters: Tiny conductive whiskers grow within an electromagnetic relay. Systems can fail if whiskers cause short-circuiting or arcing.

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 obsolescence analysis of a GPS radio for a U.S. Army helicopter found that a hardware change that required revising even a single line of code would result in a $2.5 million expense before the helicopter could be deemed safe for flight.

There is a way out of the obsolescence mess, but first we need to understand how systems became so entangled in the first place. In the United States, electronic-part obsolescence began to emerge as a distinct problem in the 1980s, with the end of the Cold War. To save money and to open up the military to the more advanced components developed by the commercial world, the Pentagon began relying much less on custom-made “mil-spec” (short for military-specification) parts, which are held to more stringent performance requirements than commercial products. This policy, called acquisition reform, affected many nonmilitary applications as well, such as commercial avionics and oil-well drilling and some telecommunications products, which had historically depended on mil-spec parts because they were produced over long periods of time. Now at least 90 percent of the components in military communications systems are commercial off-the-shelf products, and even in weapons systems the figure comes to 20 percent, mostly in the network interface. The vast majority of the memory chips and processors in military systems come from commercial sources.

A European Union–driven ban on the use of lead in electronic components that took effect in July 2006 has exacerbated the situation. Although military, avionics, and most other long-lasting systems are actually exempt from the directive, those exemptions amount to little. Consumer electronics makers aiming their products at international markets comply with the ban—which in turn pushes the IC manufacturers to remove all lead from their parts. The main consequence of the ban is that traditional solder, which contained lead, had to be replaced with a lead-free alloy that was sufficiently cheap and also had the attractive mechanical, thermal, and electric properties of lead. Many such alloys, however, tend to sprout tiny “whiskers” over time, potentially causing short-circuiting. In 2005, for example, a nuclear reactor at the Millstone Power Station, in Connecticut, was shut down because some of its diodes had malfunctioned after forming whiskers, and in 2000 a $200 million Boeing satellite was declared a total loss after whiskers sprouted on a space-control processor. Both the unavailability of lead-based parts and the unreliability of some of their replacements are very real issues that plague longer-lasting systems.

The absence of crucial parts now fuels a multibillion-dollar industry of obsolescence forecasting, reverse-engineering outfits, foundries, and unfortunately, a thriving market of counterfeits. Without advance planning, only the most expensive or risky options for dealing with obsolescence tend to remain open. The most straightforward solution—looking for a replacement part from a different manufacturer or finding it on eBay—faces substantial hurdles. For example, a part purchased from an unapproved vendor can involve costly and time-consuming “requalification” testing to determine that the replacement is entirely reliable and not counterfeit—a possibility that at the very least poses serious risks. [See “Bogus!,” IEEE Spectrum, May 2006.]

Then there's the not-so-small matter of finding the right parts, which may exist in sufficient supply but be nearly impossible to track down. John Becker, former head of obsolescence planning for the Defense Department, tells me that the Federal Logistics Information System databases encode parts made by 3M in 64 different formats. That includes small differences in the way the company's name appears, like 3M versus 3 M or MMM, and so on. And that number doesn't even count the Air Force, Army, and Navy databases, nor all the ways that Lockheed Martin, Boeing, or other contractors might keep track of 3M's parts. A standardized method for encoding names and serial numbers would eliminate a lot of obsolescence cases by making it easier to track down the original parts, close substitutes, or upgraded versions.

For truly critical cases, procurement officers can turn to aftermarket manufacturers that are authorized by companies like Intel and Texas Instruments to resurrect their discontinued integrated circuits. An original manufacturer might give Lansdale Semiconductor or Rochester Electronics uncut wafers, which can later be finished on demand. Although reliable, this custom-assembly approach costs about $54 000 (in 2006 dollars) for a production run that might yield as few as 50 units of one integrated circuit, according to a report by ARINC, an operations consulting firm. (Rochester disputes this figure, saying it can resurrect a TI wafer for between $5000 and $20 000.)

Another option is to redesign or reverse-engineer the part, but that could take 18 months. If the system in question is critical, a year and a half is simply too long. The ARINC analyses indicate that a redesign can run between $100 000 and $600 000, and even that may be conservative.

The most common plan—when a company or defense program has a plan—is to wait until a supplier announces the end of a product's manufacturing cycle and then place a final order, hoarding the extra parts the company expects it will need in order to support the product throughout its lifetime. But such lifetime purchases can turn out to be trickier than one might expect.

First, not all manufacturers send out their alerts enough in advance to allow their customers time to request a final factory run. The Government-Industry Data Exchange Program, or GIDEP, estimates that it receives about 50 to 75 percent of the obsolescence notices that are relevant to the Defense Department. That does not mean that all those alerts reach program managers before the product has been discontinued, despite the industry standard of 90 days' notice.

Second, it can be hard to know how many parts to stockpile. For inexpensive parts, lifetime buys are likely to be well in excess of forecasted demand, because a manufacturer may set a minimum purchase amount. Consider one major telecommunications company (which wishes to remain unnamed for competitive reasons) that typically buys enough parts to fulfill its anticipated lifetime needs every time a component becomes obsolete. Currently, the company holds an inventory of more than $100 million in obsolete electronics, some of which will not be used for a decade, if ever. In the meantime, parts can be lost, degrade with age, or get pilfered by another product group—all scenarios that routinely undermine even the best intentions of project managers.

The answer, then, involves more than removing bureaucratic hurdles. Better databases don't obviate the somewhat spontaneous, panic-driven responses that program managers can feel forced to make when they see that a part's production is about to cease. Ultimately, only a focus on strategies that try to predict the future can offer dramatic improvements to product managers facing component obsolescence.

Such companies as i2 Technologies, Qinetiq, Total Parts Plus, and PartMiner have produced commercial tools that forecast obsolescence by modeling a part's life cycle. To derive a forecast, the services weigh a product's technical attributes—for example, minimum feature size, logic family, number of gates, type of substrate, and type of process—to rank parts by their stages of maturity, from introduction through growth, maturity, decline, phase out, and obsolescence. At the Center for Advanced Life Cycle Engineering, my colleagues and I have added another dimension to the prediction, by mining commercial vendors' parts databases for specific market data, including peak sales years and last order dates.