The Winter Simulation Conference (WSC) is the premier international forum for disseminating recent advances in the field of system simulation. In addition to a technical program of unsurpassed scope and quality, WSC provides the central meeting place for simulation practitioners, researchers, and vendors working in all disciplines and in the industrial, governmental, military, and academic sectors. WSC'09 will feature a comprehensive program ranging from introductory tutorials to state-of-the-art research and practice. The conference includes student presentations, exhibits, training sessions by software vendors, business meetings for professional societies and software user groups, and a general reception. The theme for WSC 2009 is "Energy Alternatives".