The extraordinary breakthrough management program--heralded by GE， Motorola， and AlliedSignal--that is sweeping corporate America with its unprecedented ability to achieve superior financial results.Six Sigma is the most powerful breakthrough management tool ever devised， promising increased market share， cost reductions， and dramatic improvements in bottom-line profitability for companies of any size. The darling of Wall Street， it has become the mantra of Fortune 500 boardrooms around the world because it works.What is Six Sigma? It is first and foremost a business process that enables companies to increase profits dramatically by streamlining operations， improving quality， and eliminating defects or mistakes in everything a company does， from filling out purchase orders to manufacturing airplane engines. While traditional quality programs have focused on detecting and correcting defects， Six Sigma encompasses something broader: It provides specific methods to re-create the process itself so that defects are never produced in the first place.Most companies operate at a three- to four-sigma level， where the cost of defects is roughly 20 to 30 percent of revenues. By approaching Six Sigma--fewer than one defect per 3.4 million opportunities--the cost of quality drops to less than 1 percent of sales.This is because the highest quality also results in the lowest costs. When GE reduced its costs from 20 percent to less than 10 percent， it saved a billion dollars in just two years--money that goes directly to the bottom line. This is the reason Wall Street and corporations as diverse as Sony， Ford， Nokia， Texas Instruments， Canon， Hitachi， Lockheed Martin， American Express， Toshiba， DuPont， and Polaroid have embarked on corporate-wide Six Sigma programs.Six Sigma should be of paramount importance to every forward-thinking executive and manager determined to make their company world-class in their industry.