Six Sigma is a data-driven program focused on making processes predictable by reducing variation and defects. It uses a structured approach, typically DMAIC (Define-Measure-Analyze-Improve-Control), to define problems, measure how a process currently performs, identify root causes of variation, implement improvements, and put controls in place to maintain gains. Although it began in manufacturing, its methods apply to service processes as well, helping standardize results across different contexts. Certification and training paths (such as Green Belt and Black Belt) are common, with many organizations and independent bodies offering third-party certification. So the description that captures these elements—standardizing results, eliminating variation, and the possibility of third-party certification—best describes Six Sigma.