THE WEIGHT THING
In 1987, we contributed our concepts and early prototypes, along with the other Army research, development and engineering centers, to an advanced technology demonstration at U.S. Army Natick Soldier Research, Development and Engineering Center to show what the “Soldier of the Future” would look like. But on demonstration day, we were horrified when we all suddenly realized that everything Army labs were doing was collectively adding weight to the basic Soldier load—whether giving the Sol- diers increased ballistic protection, new rations (which required water to hydrate), optical rifle sights, night vision, computerized radios and even a new bayonet (with sharpening stone). Tere was no doubt that Soldiers needed these new capabilities, but darned if we weren’t all adding weight to our warfighters with our individual high-tech advancements.
Upon entering a major program management office with a port- folio of close combat munitions, I saw firsthand an early “bunker buster” munition development program that was canceled before it could even get off the ground—because no prospective contractor could honestly bid on our request for a 10-pound solution. Te requirements community had stood firm on that one. It would cost them time. It was years later that they eventu- ally had to accept several solutions in the 15- to 17-pound range (the FGM-172 Short-Range Assault Weapon and the Mk 153 Shoulder-Launched Multipurpose Assault Weapon).
Yep, when it comes to weight as a system or program require- ment, it can be a real biggie for you to consider. Is it a measure of your product or program success?
WEIGHT AS DESIGN CONSTRAINT Of course, our materiel development team derives our users’ requirements and translates them into design specifications. So it’s especially important for you to know this: While weight is one of many possible technical performance parameters, it’s one that affects others to perhaps a unique degree.
Just think about the trade-offs among performance parameters of range, payload, speed, mobility, fuel economy, survivability, lethality, transportability and even reliability (if stress-over- strength comes into play with various components). It might
also factor
into durability or
robustness—not-so-often-used
terms intermingled with reliability and utility. Weight can ripple through your system design like water, as second- and third-order effects are realized when things grow out of hand.
Remember that complexity is defined basically as the known and unknown interactions of many different connected pieces, and our business is the business of managing complexity. People want us to do things fast, but it’s more important to do things right. Te following examples illustrate some of the implications of being overweight.
‘I ONCE HAD A WEIGHT PROBLEM …’ Te highly successful Javelin anti-tank missile was a deeply troubled development program in the 1990s—and was almost canceled over its weight problem. Entering this program man- agement office (PMO) in the middle of the engineering and manufacturing development (EMD) phase, I learned weight was one of our four KPPs. We had known it was a risky goal right up front, along with several others. But at milestone B, we said, “We can do it.” It was a much-needed capability to replace the legacy 72-pound (and highly unreliable) Dragon missile.
We had conducted a 27-month technology maturation phase and had selected one prototype from three to take into advanced development. But we were a long way from anything that looked like a true configuration of the finished product. As EMD began, our preliminary design review had only been sufficient to map out the basic design and componentry to be “invented.”
About 18 months into our 36-month EMD phase, approaching critical design review (and before actually building a representa- tive engineering design model), we realized we were not going to be able to make the 35-pound desired (objective) or even 45-pound required (threshold) weight required by the user in the requirement document.
During a typical system development, functionality, weight, cubic dimensions, interfaces and a host of other specifica- tions are allocated to various producers. It may be quite some time before designs evolve, progress is realized and forecasting
Realizing that weight is an important parameter up front and early is important, but not nearly enough alone to alleviate weight’s programmatic perils.
136 Army AL&T Magazine April-June 2018
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