Six Sigma is a rigorous methodology that uses data analysis to identify and eliminate defects in manufacturing and business processes. It aims for near perfect production processes with only 3.4 defects per million opportunities. DMADDD is a digital process used to drive costs out of processes by automating non-value tasks. Critical to Quality factors (CTQs) are key process outputs that are important to measure. Potential causes of defects are identified and the most influential ones are targeted for improvement through tools like a cause-and-effect chart.