Six Sigma is a data driven approach for eliminating defects and waste in business processes. It is a methodology, a philosophy, and a way of doing business. Six Sigma is only one of several tools an organization needs to achieve best in class status. Companies have realized savings in amounts exceeding billions of dollars as a result of their dedication to the Six Sigma methodology.
Furthermore, Six Sigma is a statistical term that measures how far a given process deviates from perfection and provides a scientific way to measure quality and performance. In Six Sigma we use the DMAIC process (define, measure, analyze, improve, control) to guide us from the identification of a problem to successfully controlling our improvements we’ve put in place to eliminate defects from our processes. The idea is, if we can measure how many defects we have in a process we can systematically figure out how to eliminate those defects from our processes and reach as close to zero defects as possible.
Example: If our facility is manufacturing one million pouches of instant oats this week and we are striving to operate at a level of Six Sigma, then our goal is to produce 3.4 or less defects per million pouches that we produce. In this case, we would consider a pouch to be defective if its weight is outside the customers specified weight range. If we had 3.4 or less defects during the week’s run, this would be considered operating at a level of Six Sigma.
The Greek letter Sigma (σ) refers to the standard deviation of a given population. In this case it would be a calculated number based on the average of all the instant oat pouches weighed. Confused? Please continue reading. Sigma, or standard deviation, represents the amount your process is deviating from the mean (average of all pouch weights) in relation to an upper and lower specification limit. Still confused? Take a look at the chart below. If we had only 3.4 instant oat pouches outside of the upper or lower weight limit during the week’s run of one million pouches, we would be operating at 6σ.
By taking a scientific approach such as Six Sigma we learn to study the data which in turn allows us to visually see the variation and defects within our own processes. The data we gather can tell us a story about any given process. We can use some of the many tools Six Sigma offers to isolate and correct variation within our processes, identify if our process is in or out of control, locate special causes of variation in our processes, find contributing factors to the defects (critical X’s), and many more useful bits of information to assist us in removing defects and operating closer to perfection. Below is a list of some key elements to a Six Sigma approach.
Six Sigma is a vision that we must all strive to achieve and a philosophy that should be part of our culture. Some specific key elements to achieving Six Sigma are:
Customer – Keep customers happy! The customer defines what quality is. They expect their product to be on time, on budget, and free from defects.
Process – Thinking about the process from the customer’s perspective. Always look at the process from the customer’s point of view; from the outside looking in.
Employee – Must have commitment from Leadership; “flipping the triangle.” Involve all team members in the journey through training and communication.
Typically, Six Sigma projects are executed by Six Sigma Green Belts and Six Sigma Black Belts, and are usually overseen by Six Sigma Master Black Belts.
Six Sigma is a very powerful tool and should be kept in the top drawer of our continuous improvement toolbox. Through the use of this proven scientific approach, Six Sigma can guide us to drive out defects in our processes while bringing our organization one step closer to World-Class Quality. Best of the best!