This report describes a Mission Dependency Index (MDI) developed for U.S. Army facility asset management. The MDI is an indicator of mission-related importance of Army infrastructure elements to be used for the purpose of providing more effective local prioritization of facilities for sustainment, restoration, and modernization (SRM) actions. It does this by evaluating the mission impact of interrupting a function or relocating where it is provided. The index is reported on a scale of 0-100, and is analogous in that respect with existing Corps of Engineers Sustainment Management System (SMS) indices. As part of this work, an MDI methodology directly fit to Army-specific missions, facility resource capabilities, and organizational structure was developed. This was accomplished through a pilot implementation at White Sands Missile Range. The objectives of the demonstration were to identify Army-specific MDI criteria, develop a standardized implementation process, determine the steps for integrating MDI information into garrison-level and Army-level facility management business processes, and identify considerations and requirements for incorporating Army MDI criteria into the BUILDER ® SMS. The results of an MDI analysis, as facilitated using the implementation and integration procedures recommended here, will enable facility decision makers to focus on infrastructure most critical to mission effectiveness.