Six Sigma is a business management strategy, which provides proved quality management methods. It includes business and cost-benefit analysis, thought-process mapping customer surveys, control charts and regression analysis. The difference with other business management models lies in the emphasis that Six Sigma puts on measurements, as the starting point of decision making processes.
Briefly, if measurements are the road signs of your business management plan, Six Sigma provides you the map for decision-making. This method is now one of the most used by all-sized organizations.