Kabir Kassam - Six Sigma Lesson 1

As a series of processes designed for maximum workplace efficiency, Six Sigma measures and describes how, quantitatively, a business or component of that business is doing. It’s only natural that a system based largely in statistical analysis would refer to the Greek letter sigma (σ), the mathematical symbol for standard deviation (the amount of variation from the mean). Six, then, denotes the six standard deviations that exist between the average and the nearest specification limit in an ideal business process, as represented on a graph. In other words, a Six Sigma business is one where its processes produce less than 3.4 defects (results outside of product specifications) per one million opportunities, meeting a high and surprisingly achievable performance standard This can be accomplished in several ways, though two major project methodologies, DMAIC and DMADV, enumerate the criteria for improvement to existing and new processes, respectively. We will cover the differences later on.