# Six Sigma

**Six Sigma** originated as a set of practices designed to improve manufacturing processes and eliminate defects, but its application was subsequently extended to other types of business processes as well. In Six Sigma, a defect is defined as anything that could lead to customer dissatisfaction.

Six Sigma features include:

- A clear focus on achieving measurable and quantifiable financial returns from any Six Sigma project.
- An increased emphasis on strong management leadership and support.
- A special infrastructure of “Champions,” “Black Belts,” “Green Belts” etc. to lead and implement the Six Sigma approach.
- A clear commitment to making decisions on the basis of verifiable data, rather than assumptions and guesswork.

**How does it work?**

Suppose I track how long it takes to drive home after work each night – and put the data in a chart.

Next, I want to find the mean – the number that sits in the middle. In the chart above, the mean is the number 25. I’ll draw a line through the chart to show it:

Now I need to find the square root of the mean. In this case it is 5. I am going to multiply the square root times 3 (5 X 3 = 15)

If I add this to the mean, I get 40 (25 + 15 = 40) (Green line)

If I subtract this from the mean I get (25 – 15 = 10) (Yellow line)

**What does this mean?**

If I can predict the outcome of a what I do on my job, I can be much better at my job. In the case of the chart above, I can predict that my drive home each night will be between 10 and 40 minutes – between the yellow and green lines. Notice that one night, my drive home was more than 40 minutes. When a number falls outside the range, it ALWAYS has a reason that can be identified (in this case, an unexpected traffic jam).

**Six Sigma Explained**

Remember the square root of 5? Each time I add (or subtract) one square root to the mean, it is called a sigma. For example, from 25 to 30 would be 1 sigma, and from 30 to 35 would be another sigma, and so on.

As it turns out, there are SIX SIGMAS on the chart above. COOL! Here is the graphic for Six Sigma, in case you see it somewhere:

In Six Sigma, the idea is to reduce variation so that all the points fall within 1 sigma of the mean. In other words, the drive home should take between 20 and 30 minutes – or less. In a perfect world, the drive home will ALWAYS take 25 minutes EXACTLY!

That’s what the companies that are using Six Sigma as their practice are after – to reduce variation and have each product or service be exactly the same.

Six Sigma is currently one of the most popular continuous improvement activities in business – and most companies use it incorrectly because they don’t understand it. They expect a “quick fix” or “simple project” when, in fact, it takes a lot of work and effort before it pays off. When used correctly, it is a great tool.

Employees who have completed at least one Six Sigma project are called Green Belts. With more training and experience, people work themselves up to the level of Black Belts or Master Black belts. There are some organizations that teach the philosophy and will certify you as a green to black belt, but it is not the same asactually experiencing a Six Sigma project.

At this time, there is no nationally recognized certification in Six Sigma.

If you would like more information or explanation of Six Sigma please contact me. I would be happy to answer your questions.