In an effort to provide health care of optimal quality, providers traditionally assess or measure performance and then assure that it conforms to standards. In cases where performance fails to conform, providers attempt to modify or improve physician behavior. The analytic scope of this traditional paradigm may not be broad enough to allow modern health care organizations to provide optimal care. At a theoretical and practical level, many conceptual limitations inherent in the traditional approach are addressed in modern industrial quality science. A fundamental principle of industrial quality control is the recognition, analysis, and elimination of variation. Based on rigorous analysis of variation in outcomes and processes, industrial quality experts have developed principles and techniques for quality improvement. Health care organizations may well make important advances in the quality of care and service through the application of these principles and techniques.