The Commission on Planning, Programming, Budgeting, and Execution (PPBE) Reform asked RAND for an independent analysis of PPBE-like functions in selected countries and other U.S. federal agencies comparable to the U.S. Department of Defense. This executive summary distills key insights from seven case studies of budgeting processes, as detailed in two companion volumes, and compiles findings from all 16 case studies in the seven-volume series.