The Department of Defense (DOD) acquires goods and services from contractors, federal arsenals, and shipyards to support military operations. Acquisition is a broad term that applies to more than just the purchase of an item or service; the acquisition process encompasses the design, engineering, construction, testing, deployment, sustainment, and disposal of weapons or related items purchased from a contractor. This book provides an overview of the process by which the Department of Defense acquires weapon systems and discusses recent major efforts by Congress and DOD to improve the performance of the acquisition system. It also discusses the DOD's use of contractors to support military and the Nun-McCurdy Act.