Six Sigma is a data-driven approach and methodology for improving quality and efficiency in processes. Originally developed by Motorola in the 1980s, Six Sigma aims to minimize the number of defects in processes by achieving as close to six standard deviations (Sigma) from the mean of process performance, equating to a defect rate of 3.4 defects per million opportunities.
Six Sigma employs a mix of statistical methods and quality management tools, promoting the application of the DMAIC cycle (Define, Measure, Analyze, Improve, Control) for existing processes and the DMADV cycle (Define, Measure, Analyze, Design, Verify) for new processes or products.