This handbook describes the philosophy, knowledge, science, and art of decision analysis. Key insights from decision analysis applications and behavioral decision analysis research are presented, and numerous decision analysis textbooks, technical books, and research papers for detailed mathematical proofs and advanced topics are referenced for thorough and comprehensive coverage. The handbook was written with four unique features in mind. First, the book has a balanced presentation of soft skills (behavioral decision making insights, decision framing, collaboration with stakeholders, information assessment from experts, and the presentation of results to senior decision makers) and hard skills (decision analysis techniques, mathematics, and modeling). Second, the book integrates the techniques of single and multiple objective decision analysis as opposed to presenting them in separate sections of the book. Third, the book uses substantive illustrative examples that carry through and integrate the material across all of the chapters. Finally, the book presents multiple qualitative and quantitative techniques for each key decision analysis task as opposed to presenting one technique for all problems. Topical coverage includes: selecting the decision making process for interacting with decision makers and stakeholders; framing the decision opportunity; crafting decision objectives; designing alternatives to create potential value; performing modeling and analysis of alternatives to increase value; assessing value and risk tradeoffs; communicating with senior decision makers; and implementing decisions. Principles of value creation and decision making challenges are also discussed.