What is Six Sigma?
Six Sigma is one of the most well-known quality improvement methodologies, and it represents the latest incarnation of the quality movement to date. It is a structured program for improving product and process quality by pinpointing and removing inconsistencies in the manufacture and delivery of products and services. Sigma (σ) is the mathematical symbol for standard deviation and is a measure of variability. Variation is the cause of unstable processes, which leads to poor quality and unsatisfied customers. Therefore, the goal of the Six Sigma process is to reduce variation such that performance up to 6 standard deviations from the mean will fall into the customer’s desired specification limits (i.e. tightly controlled process variation).