Six Sigma follows the DMAIC model for quality improvement and problem reduction (For existing processes). This well-defined process approach consists of five phases in order:

Image Source: http://businesscherub.com/lean-6-sigma/
Figure 1: Understanding DMAIC

• Define
• Measure
• Analyze
• Improve
• Control

It is an integral part of Lean Six Sigma process, but can be implemented as a standalone quality improvement process. Indeed, it is the most preferred tool that can help improving the efficiency and the effectiveness of any organization. Within the DMAIC framework, Six Sigma can utilize several quality management tools.