Hand in Hand:
	Former GE Chairman and CEO Jack Welch (holding Subir's two books on Six Sigma) and Subir Chowdhury in a joint book signing session.

Six Sigma is a methodology that seeks to improve the quality of existing processes or products by identifying and reducing or eliminating the causes of defects (errors) and variation.  Each Six Sigma project within an organization follows a defined sequence of steps and has quantified financial targets (cost reduction or profit increase).