To stem the tide of over budget programs resulting in Nunn-McCurdy reviews, several statutory and regulatory changes have occurred to Department of Defense (DOD) acquisition policy. Begun in late 2008, the system engineering process was realigned against the Milestone acquisition governance process in DODI 5000.02. The most significant change was to require a Preliminary Design Review (PDR) for Milestone (MS) B certification. This requirement was solidified in the May 2009 Weapon Systems Acquisition Reform Act (WSARA) or Senate Bill S-454. The main thrust of these efforts was to ensure a program initiated at MS B was achievable within the available budget, schedule, and technology.