Six Sigma is a methodology for improving quality by reducing process defects. It was first introduced in the manufacturing arena as a twist on other quality methodologies. In the last couple decades, it has grown in popularity and is used in many corporate settings as well as in nonprofit and health care organizations. Six Sigma focuses on minimizing process variation, understanding and meeting customer expectations for quality and using data to make informed decisions. Individuals working in Six Sigma receive extensive training in project management, change leadership, and statistics and data analysis. They also learn about the DMAIC methodology, an approach to process improvement projects that includes five systematic steps: Define, Measure, Analyze, Improve and Control.


Six Sigma began in the manufacturing sector at Motorola in the 1980s. It then became popular starting at General Electric, where it was adapted for use in service applications.


Six Sigma is based on the principles that minimizing defects is critical to ensuring quality, that customers define what quality actually is and that decisions should be made based on data rather than beliefs or anecdotal evidence.


Six Sigma allows organizations to effectively measure and understand their processes, identify and counter the causes of problems and increase satisfaction for customers, employees and other stakeholders.


Black Belts are dedicated full time to conducting process improvement projects and assisting leaders with understanding and implementing Six Sigma principles. Green Belts do this part time, and a Quality Leader or Six Sigma Director oversees the Six Sigma program.


Six Sigma uses a wide variety of techniques to understand and manage processes and make improvements. They include creating detailed maps of a process, designing effective experiments and creating a dashboard of summary metrics to describe business operations at a high level.

Data Analysis Tools

Six Sigma incorporates the use of statistics and data analysis for understanding the situation and confirming root causes and effective improvements. Project teams use a variety of charts and metrics to accomplish this, and team members learn to interpret them appropriately.