Six Sigma is one of the most important and popular developments in the quality field. It has saved huge amounts of money and improved the customer experience for a large number of organizations across the world, yet it is applied in an inconsistent and often reductive fashion in many companies. This has led to criticism in the literature and a number of abandoned implementations. This study guide is designed to provide an overview of the key elements, important historical context and current debates in the field of Six Sigma. It aims to give a coherent view of the underlying principles,.