Semmelweis demonstrated the efficacy of hand hygiene in dramatically reducing maternal deaths in hospitals from puerperal fever. Ever since, the goal of achieving and sustaining high rates of compliance with hand hygiene protocols has generally eluded hospitals. The Joint Commission Centre for Transforming Healthcare was to apply the tools and methods of Lean, Six Sigma, and change management to address the most difficult safety and quality problems facing health care. These tools, to which we refer collectively as Robust Process Improvement, have long been effectively employed in business and, more recently, in health care RPI differs from long-standing efforts that emphasize evidence-based guidelines, checklists, and toolkits, all of which are typically not customized to the setting.RPI provides new ways of examining complicated problems and discovering highly effective, targeted interventions. In keeping with its objective to transform health care into a high reliability industry, the Centre convenes teams from hospitals and health systems from across the United States that have mastered the RPI tools with RPI experts from the Centre. The Hand Hygiene Project designed to improve hand hygiene compliance at the eight participating hospitals. This project involved increasing compliance with already existing hospital policies and because all staff was expected to comply, Institutional Review Board approval was not required. Eight hospitals were selected for the project from a larger group of 16 Centre-participating hospitals with RPI expertise. The eight hospitals had ranked hand hygiene as first or second on their list of important quality and safety problems. The Centre convened teams from the eight participating hospitals to plan and then implement the project. The teams from each hospital most commonly consisted of an RPI expert and a physician specialist in infectious diseases or an infection control professional. The project followed the general outline of a typical, five-step Six Sigma project w