Six Sigma offers the advantages of being customer driven, encompassing a company's entire production or service process, facilitating proactive management, and a focus on preventing manufacturing defects. The disadvantages of Six Sigma are that it creates a rigid, bureaucratic process and the cost of achieving its goals can harm profits.
Six Sigma is defined as a limit of 3.4 defects per 1 million products or service processes. A defect is defined as any product of service that is not acceptable to the customer. It can take companies many years to achieve Six Sigma status. By addressing the entire process in order to achieve the required defect rate, companies make many improvements in the process of striving for the Six Sigma distinction.
The downside of striving for Six Sigma status is that the extreme focus on customer satisfaction can damage the company. Many enterprises, especially small manufacturers, often choose to implement quality control processes that are too costly to justify themselves. Though these companies may earn Six Sigma status, they may harm their profitability in doing so.
Six Sigma was developed by Motorola. It was soon adopted by GE, with excellent results. The success of GE led to the wide adoption of Six Sigma in a variety of manufacturing industries.