This document provides an introduction to Six Sigma, including its history, definitions, methodology, and applications for technical writers. It describes how Six Sigma originated from earlier quality management techniques and was developed at Motorola in the 1980s. The core of Six Sigma aims to reduce defects through statistical analysis and process improvement. An imaginary case study demonstrates how the DMAIC methodology could be applied to reduce errors in technical documentation. It outlines defining the problem, measuring the current process, analyzing causes of errors, improving the process, and controlling quality going forward. The document also briefly discusses Design for Six Sigma and training levels for Six Sigma practitioners.