Book excerpt: In this book we have introduced the basics of the federal budget process, provided an historical background on the foundation and development of the budget process, indicated how defense spending may be measured and how it impacts the economy, described and analyzed how Planning, Programming, Budgeting and Execution System (PPBES) operates and should function to produce the annual defense budget proposal to Congress, analyzed the role of Congress in debating and deciding on defense appropriations and the politics of the budgetary process including the use of supplemental appropriations to fund national defense, analyzed budget execution dynamics, identified the principal participants in the defense budget process in the Pentagon and military commands, assessed federal and Department of Defense (DoD) financial management and business process challenges and issues, and described the processes used to resource acquisition of defense war fighting assets, including reforms in acquisition and linkages between PPBES and the defense acquisition process.