This chapter describes the activity-based methodology (ABM), an efficient and effective approach to-ward development and analysis of DoD integrated architectures that will enable them to align with and fully support decision-making processes and mission outcomes. ABM consists of a tool-independent disciplined approach to developing fully integrated, unambiguous, and consistent DODAF Operational, System, and Technical views in supporting both “as-is” architectures (where all current elements are known) and “to-be” architectures (where not all future elements are known). ABM enables architects to concentrate on the Art and Science of architectures—that is identifying core architecture elements, their views, how they are related together, and the resulting analysis used for decision-making purposes. ABM delivers significant architecture development productivity and quality gains by generating several DoDAF products and their elements from the core architecture elements. ABM facilitates the transition from integrated “static” architectures to executable “dynamic” process models for time-dependent assessments of complex operations and resource usage. Workflow steps for creating integrated architecture are detailed. Numerous architecture analysis strategies are presented that show the value of integrated architectures to decision makers and mission outcomes.