With the start of the second millennium, the Army is faced with unprecedented challenges to adequately meet current and future personnel requirements. This paper applies dynamic systems simulation as a decision support tool in meeting the changing manpower requirements of the 21^st century Army, specifically addressing the Chief of Staff of the Army's force allocation and transformation guidance. Using a systems approach to model manpower needs, the simulation integrates force attrition and retention, recruiting, force allocation, and enlisted life-cycle management concerns into a comprehensive dynamic systems model. The model output provides feasible policy alternatives to assist decision makers in managing the complexities of the enlisted personnel management system.