You may have overheard a conversation at the water cooler or read an article in a trade journal about Black Belt training. “What does martial arts have to do with project management?,” you thought. “What is this thing called Six Sigma?”
For those that are unfamiliar with Six Sigma, I have demystified the key concepts in an effort to show you how it can save your organization money while aiming to satisfy your customers.
Six Sigma is a statistical concept that measures a process in terms of defects. Achieving "six sigma" means your processes are delivering only 3.4 defects per million opportunities (DPMO) - in other words, they are working nearly perfectly. Sigma (the Greek letter σ) is a term in statistics that measures standard deviation. In its business use, it indicates defects in the outputs of a process, and helps us to understand how far the process deviates from perfection.
A sigma represents 691462.5 defects per million opportunities, which translates to only 30.854% of non-defective outputs. That is obviously a poor performing process. If you have a process functioning at a three sigma level, that means you're allowing 66807.2 errors per million opportunities, or delivering 93.319% non-defective outputs. That's much better, but we are still wasting money and disappointing our customers.
How well are your processes operating? Are they three sigma? Four sigma? Five?
The central idea of SIx Sigma management is that if you can measure the defects in a process, you can systematically figure out ways to eliminate them to approach a quality level of zero defects.
In short, Six Sigma is several things:
- A statistical basis of measurement: 3.4 defects per million opportunities
- A philosophy and a goal: as perfect as practically possible
- A methodology
- A symbol of quality
Six Sigma stems from the quality movement that started after World War II. Six Sigma was originally developed for Motorola in 1986 by Bill Smith. It was conceptualized as a quality goal at Motorola because technology was becoming so complex that traditional ideas about acceptable quality levels were inadaquate. In 1989, Motorola announced a five-year goal - a defect rate of not more than 3.4 million parts per million - six sigma.