In 1997, with the Cold War well behind them, thousand of engineers who had helped design and maintain the B-2 bomber were asked to leave the integrated systems sector of Northrop Grumman. As the nearly 12,000 workers filed out the door, leaving only 1,200 from a staff of 13,000, they took with them years of experience and in-depth knowledge about what was considered at the time to be the most complex aircraft ever built.

Northrop Grumman knew it had to keep enough of that know-how to support the division’s long-term maintenance of the B-2 bomber, so a newly formed knowledge management team identified top experts and videotaped interviews with them before they left. But it was hard to get everything in a single interview, says Scott Shaffar, Northrop Grumman’s director of knowledge management for the Western region of the integrated systems sector. "We did lose some of that knowledge," says Shaffar. "In an exit interview, you can capture certain things, but not a lifetime of experience."

Northrop Grumman scrambled at the time to identify experts in key areas related to the program and to create a central repository for project documents. The aerospace giant kept enough of that knowledge to maintain and move forward with B-2-related upgrade projects, even as some expertise disappeared. Still, Northrop Grumman learned some important lessons about preventing a massive brain drain in the future.

Eight years later, the company uses a variety of tools to retain and transfer knowledge from its engineers—well before they retire. Shaffar and his team have put in place document management systems and common work spaces that record how an engineer did his job for future reference. They have started programs that bring together older and younger engineers across the country to exchange information via e-mail or in person about technical problems, and they are using software that helps people find experts within the company.

While most companies won’t face the sudden departure of thousands of skilled workers, as Northrop Grumman did in the late 1990s, they and government agencies alike will need to prepare for the loss of important experience and technical knowledge as the baby boomer generation gets ready to retire over the coming decade. By 2010, more than half of all workers in the United States will be over 40. As of 2005, the baby boomers (the generation born after World War II) range in age from 41 to 59, and their numbers almost double the Generation X that follows them. And unlike their younger counterparts, many boomers have spent a large chunk of their careers in one company or agency, building up stores of experience and knowledge. While some KM experts downplay the issue, claiming that younger generations will take over and bring new skills as their older colleagues retire, it is clear that many companies are already feeling the pinch as those on the older fringe have started to leave the workforce. According to a study by AARP, more than 60 percent of U.S. companies are currently bringing back retirees as contractors or consultants.