Book excerpt: This monograph addresses the following two specific questions: What should a robust acquisition investment strategy look like-one designed to perform well against all anticipated threats? How should the Army acquisition community assess the appropriateness of its investment strategy over time? The study proposes adaptation of a RAND tool called Assumption-Based Planning to help Army personnel maintain proper alignment between strategic guidance and the Army acquisition program and budget. It uses this tool to create a model that recommends acquisition investments across a broad range of capabilities. The model works toward the goal of satisfying the complex and evolving requirements specified in the national security guidance. The model applies five main steps, by identifying (1) the assumptions that underlie Army acquisition policy; (2) load-bearing assumptions, i.e., important assumptions that underpin and shape Army acquisition plans; (3) signposts or indicators that an assumption is becoming vulnerable; (4) shaping actions that can be taken to keep assumptions viable, and (5) hedging actions that can be taken to prepare for unwelcome but unpreventable developments. For the acquisitions community, shaping and hedging actions both take the form of investments.