A rapidly changing national security environment and rapidly evolving technologies have led to concerns that Department of Defense (DOD) acquisition is not sufficiently responsive to operational needs. In response to a provision in DOD’s Better Buying Power 3.0 initiative, IDA conducted research focused on the “cycle time” of DOD acquisition processes—i.e., how long it takes to acquire and field new force capabilities. DOD has taken various approaches in the past to accelerate weapon system acquisitions. IDA selected several historical acquisition programs, each of which was accelerated (either successfully or not) in different ways and in response to different operational needs. The research found that acquisition programs should be accelerated when the value of having the capability sooner is compelling, weighed against the risks of rushing the acquisition process. That tradeoff requires a balancing of current and projected requirements with existing and expected technologies available to meet them. When the tradeoff favors an accelerated acquisition, the research identified several keys to success. Timely innovation to meet future needs requires a coordinated program of technology development linked with prototyping and operational experimentation and employment. Processes to achieve those ends exist to some extent but must be revitalized and funded with higher priority.