Six Sigma was born anywhere from 20 to 50 years ago, in corporate engineering communities in Japan, which are in the habit of reducing processes to statistically measurable phenomena (the cornerstone of Six Sigma). It started its journey towards North America about 25 years ago, with Motorola launching its Six Sigma program in early 80’s. About the same time, GE also launched a Six Sigma Program.
Errors, low productivity, inaccuracies, procedural malpractices and substandard products cost organizations in terms of scrap, warranty claims, litigation and most of all lost business. If we are to reduce errors and improve quality substantially, we must create systems and processes that anticipate inevitable errors and either prevent them or compensate for them before they cause harm.
Six Sigma is a philosophy that seeks to understand how systems permit and even facilitate the occurrence of errors, in contrast to the traditional practice of blaming errors on individuals. The tools it provides measure and reduce unwarranted variations in practices to improve outcomes. It is the best-known “revolutionary” performance improvement method that utilizes numerous statistical tools to streamline the whole system so that the probability of error is reduced to 2 in a billion opportunities (or 99.999998% accuracy). Following table gives a comparison between the performance at 6 sigma as compared to 3 sigma
Table 1: Comparison of Performance at Three Sigma with Six Sigma
|At Three Sigma (99.73% accuracy)||At Six Sigma (99.999998% accuracy)|
|Virtually no modern computer would function.||2 computers in a billion would be defective|
|4,050 invoices would be sent out incorrectly each month by a modest-sized company.||2 invoices would be sent out incorrectly in 50 years by similar company|
|16,694 Erroneous business orders [250,000 opportunities per year]||0.9 Erroneous business orders [250,000 opportunities per year]|