This document provides an introduction to Six Sigma and Lean methodologies. It discusses the history and origins of Six Sigma, which began in the 1980s at Motorola to reduce defects. Six Sigma aims to reduce process variation and improve quality to near-zero defect levels. It uses a define-measure-analyze-improve-control problem-solving approach and statistical tools. The document outlines key Six Sigma concepts like the six sigma metric of 3.4 defects per million opportunities and the importance of understanding and reducing variation. It also discusses Lean and how Six Sigma and Lean methodologies can be integrated for process improvement.