(Editor's Note: The second-to-last paragraph in this story has been updated to reflect that pressing to reduce expenditures using the should-cost tool is not meant to trade away "long-term value of sound design practices and disciplined engineering management for short-term gain," Carter cautions.) The Pentagon's acquisition executive is moving to dispel "understandable confusion" among Defense Department procurement officials about how and when to implement two policies central to the Obama administration's efforts to wring inefficiency and new savings...