Six Sigma is a business management
strategy, originally developed by Motorola in 1986. Six Sigma became
well known after Jack Welch made it a central focus of his business
strategy at General Electric in 1995, and today it is widely used in
many sectors of industry.
Six Sigma seeks to improve the quality of
process outputs by identifying and removing the causes of defects
(errors) and minimizing variability in manufacturing and business
processes.
It uses a set of quality management
methods, including statistical methods, and creates a special
infrastructure of people within the organization (“Black Belts”, “Green
Belts”, etc.) who are experts in these methods.
Each Six Sigma project carried out within
an organization follows a defined sequence of steps and has quantified
financial targets (cost reduction and/or profit increase).
The term Six Sigma originated from
terminology associated with manufacturing, specifically terms associated
with statistical modeling of manufacturing processes.
The maturity of a manufacturing process
can be described by a sigma rating indicating its yield, or the
percentage of defect-free products it creates.
A six sigma process is one in which
99.99966% of the products manufactured are statistically expected to be
free of defects (3.4 defects per million).
Motorola set a goal of “six sigma” for
all of its manufacturing operations, and this goal became a byword for
the management and engineering practices used to achieve it.
