Six Sigma Overview


Six Sigma is a philosophy of business management which aims to improve the quality of the process. It focuses on identifying and eliminating the causes of defects and variations in business and manufacturing processes across the various sectors of the industry and is being used as the effective quality management strategy.

Meaning What is Six Sigma

In Statistics the standard deviation is represented by the Sigma (the lower-case Greek letter ?) and Six Sigma refers to the Six Standard Deviations. A process is Six Sigma Process when it has six standard deviations between the mean of the process and the nearest specification limit thus looking to achieve the perfection in quality measures.  Statistically a process is Six Sigma process if it produces 3.4 defective parts per million opportunities (DPMO). Here defect refers to the anything which is outside the defined limits which may leads to customer dissatisfaction. Opportunity refers to the total number of chances of defect.

Historical Overview

In 1986, Bill Smith at Motorola had formulated the methodology of Six Sigma. It is trademark of Motorola. It adopts  the best practices of the previous quality improvement methodologies like TQM, Zero defects e.t.c .  and adds some of the unique features of its own. It was evolved in the manufacturing sector however later on it got spread to the various different sectors of the industry.

Six Sigma quality improvement initiatives includes a well defined infrastructure of “Champions”, ‘Master Black  Belt”, “Black belt” who are responsible for implementing the Six Sigma principles. They ensure that any  Six Sigma project will yield an measurable and quantifiable gains for the organization. Decisions are always based on the data and role of outstanding leadership in leading the organization is emphasized.


Six Sigma improves the existing business process by focusing on continuous efforts which leads to stable and predictable results related to the process ensuring quality improvement.   It follows the strategy which is measurement based wherein a process can be measured, analyzed, improved and controlled.  It implies that in order to achieve the business success through quality control, everybody in the organization should be commited. It applies various quality management methods, various tools, resources and qualified professionals having required level of expertise.

Leave a Reply

Your email address will not be published. Required fields are marked *