Component obsolescence is a concern across system development
Component obsolescence is nothing new, and the problem isn't going away. While electronics innovations may move industry forward on one hand, the downside is that some electronics get left in the dust, no matter how widely adopted they may have been at one point.
Look at the PowerPC Altivec, for example: This powerful processing architecture had an extremely loyal install base, yet for reasons unknown to most of us, it was dropped for several years, forcing its customers to look for other processing alternatives. Although Altivec recently returned in the T4x series of the PowerPC system-on-chip (SoC) devices, the growing use of other processors supplanted the device series, effectively muting its once-untouchable popularity. Other examples of component obsolescence may not be as complex or daunting as the Altivec case, but the example stands as a warning: Component functionality that once existed in abundance can seemingly disappear overnight.
While the evolution of electronics is one main reason causing obsolescence issues, there are also a few other significant factors influencing this. For military and aerospace system designers and suppliers, these factors hit home harder than in some other industries.
Business factors affecting obsolescence
Unfortunately, the proper operation of mission-critical and highly sensitive military electronics sometimes takes a back seat to other, seemingly more pressing, concerns of semiconductor companies, such as increased yields and profits. The early demise of any one component basically moots these business factors. In fact, component obsolescence is occurring more frequently, and even sooner than was the norm, in many military program production cycles.
A recent point of contention regarding some electronic components in the defense community is the transition away from lead in electronic components [Pb <3 percent] (specified by EU mandate), allowing an almost-forgotten 80-year-old problem to rear its ugly head in the component supply chain: Yes, we’re talking about tin whiskers.
For non-mission-critical applications, failure of a system may not rank as high as profitability, according to those in the early part of the supply chain. The use of non-lead solder balls on ball grid array (BGA) devices saves enough money that the component manufacturers tolerate certain criticism from system designers. For military missions, however, where the use of lead alloy ensures that tin whiskers do not occur, and security and human lives are on the line, any level of failure is unacceptable.
As suppliers continue to remove higher-cost lead alloys from components, the percentage of tin used is increasing. For telecommunications equipment and military/defense systems, components then need to be retrofit to meet the high reliability specifications of the application.
This spec is typically accomplished by replacing the >97 percent tin alloy composite with a mix that includes the proper amount of lead to offset the growth of the tin whiskers. The unintended result is yet another cost added to military components and their programs, a cost that most heavily scrutinized programs cannot bear.
Managing availability beyond the components
Having to deal with parts that are no longer in step with the higher reliability specs isn’t the only aspect of component obsolescence. The underlying technical expertise and long-term life cycle sustainability of a program are just as important. Even at the onset of product development today, component obsolescence must already be paramount in the mind of the product developer, with an eye towards mitigating the obsolescence costs in the future for users.
As embedded computing companies continue to design and build technologically advanced, reliable commercial off-the-shelf (COTS) products, they should also be thinking about how the customer will be supported long-term. In-depth technical knowledge needs to be shared cross-functionally to ensure continuity. Additionally, retiring talent with that expertise needs to be replaced with newer engineering resources to plan for future program developments.
In the military/defense and aerospace industries, in which programs can take years and millions of dollars to develop, test, and qualify, all of these aspects definitely figure into obsolescence concerns. These embedded systems aren’t like the latest cellphones, easily discarded when the next upgrade comes along. They’re comprised of rugged or even military-grade single-board computers (SBCs), enclosures, I/O, and graphics products that take time and money to create. They must be available for the long haul as programs move from low-rate initial production (LRIP) to full production cycles.
A process designed to mitigate
The lifecycle of COTS products needs to be managed according to a well-defined and forward-looking program. At Aitech, for example, the COTSLifecycle+ program is divided into three distinct program phases: Active, Supported, and Extended Support, each of which provides product availability for at least four years. The combined life cycle ensures a minimum COTS product lifetime of 12 years from product introduction, and usually far longer. Employing total program and life cycle support services ensure that the products that are designed in today will meet the functional, environmental, and operating requirements of the specifications of tomorrow.
Electronic systems have always consisted of both active and passive components. In time, these components are replaced by the next generation of more technically capable components, resulting in the obsolescence of the earlier devices. This is a natural progression, but by implementing a structured approach that thinks ahead of the next electronics evolution, designers can effectively guard against, or at least prolong, such obsolescence. (Figure 1.)
Designing for the future
No matter how you parse the problem, component obsolescence equals added costs – in many instances unplanned and unbudgeted – that translate into program delays and cost overruns. Even with a modular, preplanned technology insertion roadmap, early component obsolescence is hard to predict and even harder to counter, unless companies plan for it long before it happens.
Managing obsolescence needs to happen on many different levels and should be shared all the way from component manufacturer through to the end user. It’s not the job of just one link in the supply chain to assume all of the burden to ensure longevity of these highly integrated, rugged embedded systems. From the actual parts to availability and through to design resources, many factors can impact how far from its starting point an embedded system design may need to wind up.
Warfighters must have access to the most advanced technology available, and military systems must be held to the most stringent standards of quality and reliability. Neither of these factors is going to change. While system designers may not be able to eliminate all the factors affecting obsolescence, recognizing them will enable proper planning in terms of time to market and preplanning for the resulting cost adjustments.
Aitech Defense Systems www.rugged.com