Six Sigma is a quality control technique that is used to detect or minimize the occurrence of defects in a given process which improves the overall quality standard. The Six Sigma approach focuses on improving the faulty process by acting on the cause of the defect instead of the defect itself. This means it concentrates on the process instead of the machinery, the product or the employees. This technique can yield remarkable savings in cost, increases in productivity and reduced turn around and lead times. The Six Sigma system is used by many types of manufacturing industries as well as service companies.
The Six Sigma program originated in the 1970s and became more commonly used in the late 1980s. The process was developed as a system to help manufacture the perfect product. This of course all leads to profit making as products that have fewer or no defects means better quality, which means satisfied customers and clients, and increased sales of the product or service.
The Six Sigma program relies on statistical analysis to achieve its goals. Sigma is a word that is used in statistics to define how far a product or service strays from the norm or the perfect example. The higher the sigma number is means the more perfect the product or service is. Before Six Sigma was introduced, many quality management systems used three or four levels of sigma. Three sigmas equates to 67,000 defects per million.
There are six levels in the methodology of Six Sigma that signify the number of defects or errors occurring per million products. For example, if a company produces one million components of a particular device, then the acceptable number of times that a defective component can be produced is only 3.4. This translates to mean that the process has a quality output of 99.9997 percent.
Any process that is certified as Six Sigma must conform to the accuracy levels of 99.9997 percent or better. Six Sigma principles are not only applicable in manufacturing or production units, but also in various activities of industry, which have a definite, measurable output.