The Department of Defense (DOD) plans to increase its investment in new weapons to about $60 billion in fiscal year 2001-a 40-percent increase over fiscal year 1997. DOD has high expectations from this investment: that new weapons will be better and less expensive than their predecessors and will be developed in half the time. With its traditional management approach-which has produced superior weapons, but at much greater cost and time than planned-DOD will not meet these expectations. Leading commercial firms have changed their practices for developing products and have achieved the kinds of results DOD seeks. Maturing new technology before it is included in products is one of the main determinants of these firms' successes. This practice holds promise for DOD, for immature technologies have been a main source of problems on weapon systems. In response to a request from the Chairman and the Ranking Minority Member, Subcommittee on Readiness and Management Support, Senate Committee on Armed Services, GAO assessed (1) the impact of technology maturity on product outcomes, (2) best practices for managing new technologies and incorporating them into products, and (3) ways DOD can adapt these practices to get better outcomes on weapon system programs.