The Decision Model and Notation (DMN) standard is transforming the practice of business decision management. Instead of "harvesting" business rules in text-based requirements documents handed off to programmers, business users themselves now can create true decision models that serve either as verifiable implementation requirements or complete, fully executable decision services. Completely revised from the original edition and updated to DMN 1.2, the book guides business users through the use of DMN, including creation of Decision Requirements Diagrams, decision tables, basic FEEL expressions, and invocation of more complex logic expressions created by others. It explains proper use of the DRD shapes and symbols, literal expressions in FEEL, and use of decision table analysis to ensure the decision logic is complete, consistent, and properly contracted and normalized. Even though the models are defined graphically in diagrams and tables, they are fully executable. The book shows how to execute decision logic directly in the modeling tool to test its correctness, and even how to deploy decision models as executable REST services in the cloud.