Six Sigma is a process quality improvement method that aims to reduce process variation and defects. It was developed by engineer Bill Smith at Motorola in 1986 and focuses on reducing variability to near zero. The goal of Six Sigma is to improve processes by identifying and eliminating defects and minimizing variability in manufacturing and business processes. It uses data and statistical analysis to measure and improve processes. Companies that implement Six Sigma see improved quality, reduced costs and increased customer satisfaction.