The purpose of QC programs is to achieve the quality standards established by the customer by the reduction of variation in organizational outcomes, which inevitably reduces costs. Accordingly, without the financial benefits or cost information known and measured, a QC program is producing only half of its potential benefit. Early QC systems amounted to little more than rigid supervisory oversight (basic top-down systems). Under the influence of Japanese management styles of the 1980's and 1990's, emphasis in QC programs in the United States evolved into initiatives designed to increase worker satisfaction and therefore productivity (bottom-up components). Currently, many QC programs are incorporating the best practices of the top-down approach with best practices of the bottom-up approach. Augmenting these approaches are statistical modeling tools and experimental design approaches that result in measures of the dollar value of changes that improve quality. This QC approach, which is becoming known as "Six Sigma" systems, requires an agency to know itself, its processes, and its people, as well as its customers. The term "six sigma" is borrowed from statistics to indicate variation or standard deviation. An example of a routine QC audit under this system is provided.