Abstract: U.S. federal government spends billions of dollars each year to develop, acquire and build major systems, develops cutting-edge technologies and integrates into large and complex system, in order to enhance the performance of weapon systems. However, with the systems becoming more and more complex, the risks become a hot issue. The risk assessment system for major defense acquisition programs and projects based on best practices has been established in this paper, and the technical risk, schedule risk and cost risk are analyzed, including assessment process, assessment criteria, and case studies. Finally, some suggestions are given to risk assessment and management for defense weapon system, including technology readiness assessment, cost estimation and assessment, and schedule assessment should be considered comprehensively, and policies, laws, standards and guidance for defense weapon systems’ risk management should be established in the future.

Key words: risk assessment, technology readiness assessment, cost estimating and assessment, schedule assessment