Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of deficiencies and minimizing variability in business processes. This is one of the most effective method in business processes optimization area. The goal of Lean Six Sigma is to obtain significant improvements of business activities trough processes optimization.

It uses a set of quality management methods, including statistical methods. Each Six Sigma project carried out within an organization follows a defined sequence of steps and has quantified financial targets (cost reduction and/or profit increase).