Summary: This report examines how best practices offer improvements to the way the Department of Defense (DOD) develops new weapons systems, primarily the design and manufacturing aspects of the acquisition process. Knowledge about a product's design and producibility facilitates informed decisions about whether to significantly increase investments and reduces the risk of costly design changes later in the program. Leading commercial companies employ practices to capture design and manufacturing knowledge in time to make key decisions during product development. First, the companies kept the degree of the design challenge manageable before starting a new product development program by using an evolutionary approach. Second, the companies captured design and manufacturing knowledge before the two critical decision points in product development: when the design was demonstrated to be stable--the second knowledge point--and when the product was demonstrated to be producible at an affordable cost--the third knowledge point. DOD has made changes to its acquisition policy in an attempt to improve its framework for developing weapons systems, but the policy does not require the capture of design or manufacturing knowledge or sufficient criteria to enter the system demonstration and production phases. In addition, it does not require a decision review to enter the demonstration phase of product development.