"In the face of challenges to acquire and support the numbers and types of ships needed to meet national security requirements in an environment of rapid change and shrinking defense budgets, this report explores the U.S. Navy's options for extending the service lives of operational ships by adopting the concepts of modularity and flexibility in ship design. These concepts can help to mitigate the risks of uncertain future missions and technologies to which ships will need to adapt, as well as potentially reduce modernization costs and/or initial cost. The report examines the concepts of modularity and flexibility, technological trends, the current geopolitical context, and lessons from past incorporation of new missions and technologies into naval ships. It also provides a roadmap for future U.S. Navy modularity and flexibility efforts"--Publisher's description.