The Six Sigma method takes its name from a statistical term used to measure variation in a process. In statistics, "sigma" (σ) represents the standard deviation of a set of data, which is a measure of the dispersion or variability of values in relation to the mean.

Meaning of "Six Sigma

Six Sigma literally means "six standard deviations". In the context of process quality, this translates into a performance where 99.99966% of products or services are free from defects. In other words, this corresponds to a maximum of 3.4 defects per million opportunities (DPMO). This highly ambitious target is aimed at almost completely reducing errors and variations in industrial and commercial processes.

Origin of the Method

The Six Sigma method was developed by Motorola in the 1980s. It was introduced by engineer Bill Smith in 1986, with the support of Motorola's CEO at the time, Bob Galvin. The aim was to address quality and process variability issues that were affecting customer satisfaction and production costs.

Motorola found that traditional quality management methods were not sufficient to achieve the desired levels of performance. By combining rigorous statistical techniques with a structured methodological approach, the Motorola team was able to develop an effective strategy for identifying, measuring, analyzing, improving and controlling processes. This strategy was dubbed "Six Sigma", in reference to the statistical performance target it was designed to achieve.

Adoption and evolution

The success of Six Sigma at Motorola soon attracted the attention of other large companies. General Electric, under the leadership of Jack Welch, was one of the first to adopt and popularize the method in the 1990s. Since then, Six Sigma has been widely adopted in sectors ranging from manufacturing and healthcare to financial services and information technology.

Conclusion

The Six Sigma method is so called because of its aim to reduce process variations to a very low level, corresponding to six standard deviations from the mean. Developed by Motorola in the 1980s, it revolutionized quality management by introducing a systematic, statistical approach to continuous process improvement.

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