Introduction

The main concepts that Six Sigma uses date back to the eighteenth century and were created by people who found ways to describe chaos, randomness or astronomical phenomena, through mathematical equations such as Pierre Laplace, Abraham de Moivre and Carl Friedrich Gauss. In statistical terms, sigma represents the standard deviation; a measure of the variability within a population around the mean. In the business world, especially in manufacturing or quality management, the term Six Sigma usually refers to a set of tools and methodologies developed by Motorola to improve processes by eliminating defects. When Six Sigma becomes a philosophy of quality, its meaning is no longer restricted to the simple 3. 4 defects per million opportunities metric. Many of the companies have adopted Six Sigma principles and concepts as the fundamental philosophy of their corporate cultures. The same Six Sigma principles that make air travel a high sigma service can be applied to other services within the appropriate cost restraints.