Six Sigma is a set of strategies, techniques, and tools for process improvement whose origin can be traced to Bill Smith, an engineer who worked for Motorola. He is often referred to as the “Father of Six Sigma”. After graduating from the US Naval Academy and the University of Minnesota School of Management he has worked almost 35 years in engineering and quality assurance.

In 80’s he approached then Motorola’s CEO Bob Galvin and suggested to focus on defects caused by manufacturing process variation. Bill Smith believed that achieving drastic decrease in defects was possible by eliminating variation. This would result in less waste, increased savings and customer satisfaction. In 1987, Galvin launched a long term quality program, called “The Six Sigma Quality Program”. The program was a corporate program which established Six Sigma as the required capability level to approach the standard of 3.4 defects per million opportunities (DPMO). This new standard was to be used in everything: in products, processes, services and administration. Motorola achieved several billion dollars in savings as a result of Six Sigma approach.

Since Motorola’s successful introduction of Six Sigma system, many other global companies followed suit. In 1993, inspired by Motorola’s success, Larry Bossidy the CEO of Allied Signal decided to adopt Six Sigma system. Shortly after, Jack Welch, then Chairman and CEO of General Electric introduced this innovative quality management system to his company. Currently many global companies use Six Sigma for quality management and improvement. Just to name few: Intel, Honeywell, Toshiba, Vodafone, Samsung Group, Bank of America and Chevron.

Even though Six Sigma system gained prominence in 80’s, its cornerstone concept of statistical quality control can be traced to Walter Shewhart and Edward Deming in the first half of the XX’s century.

Walter Andrew Shewhart was a physicist, engineer and statistician often referred to as the father of statistical process control. After earning PH.D in Physics from University of California Berkley, he joined the Western Electric Company in 1918.  In order to assist Bell Telephone engineers avoid transmission equipment defects, Shewhart wrote a memorandum where he identified process variation as a main reason for causing defects. He also used control charts to demonstrate two key causes of variation: special-cause and chance-cause. Shewhart showed that keeping manufacturing process in control would drastically reduce variation.

Shewhart’s ideas were furthered by his student Edwards Deming who held Ph.D in mathematics and physics from Yale. Deming met Shewhart at Bell Telephone Laboratories in the late 1920s while studying at Yale. In 1939, Inspired by his mentor’s work Deming published a series of Shewhart’s lectures at USDA into a book – Statistical Method from the Viewpoint of Quality Control. The book helped spread the ideas of statistical process control and control charts