Six Sigma is a data-driven methodology for eliminating defects in manufacturing and business processes. It aims to reduce variation and errors through statistical methods. Key aspects include defining critical quality attributes, measuring defects and process capability, analyzing sources of variation, improving processes through design changes, and controlling processes through statistical process control methods. The DMAIC and DMADV methodologies provide frameworks for improving existing processes and designing new defect-free processes. Six Sigma has been widely adopted by major companies and yielded significant cost savings and quality improvements.

1. What is Six Sigma?