What is Six Sigma

What is Six Sigma

What is Six Sigma

Six Sigma is a business management strategy originally developed by Motorola, USA in 1981. Six Sigma is, basically, a process quality goal.

Motorola invented Six Sigma as a transformational quality and business improvement methodology, and over the last 20 years, this approach has been adopted by hundreds of companies around the world.

The traditional quality paradigm defined a process as capable if the process's natural spread, plus and minus three sigma, was less than the engineering tolerance. Under the assumption of normality, this translates to a process yield of 99.73 percent.

To understand six sigma, let's take an example of a Tyres Manufacturing company. Suppose this company produces 100,000 tyres a day. It's practically not possible to check each and every Tyre manually to verify whether it is defect free or not. So what is done is to take a random sample of this manufactured tyre and look for defects.

Assume that the thickness of the tyre is a parameter to measure defect. So if any tyre has a thickness less than 10 mm, it is considered to be defective.

Now, if you measure the actual thickness of all these 100, 000 tyres manufactured daily, and plot them on a graph, you would most probably have a Bell shaped graph, with majority of the tyres having thickness very near to the mean thickness. Such graphs are also called Normal Distribution graph.

It is called Normal distribution, because any large volume of data if plotted would against some parameter would most probably be in a Bell shaped curve.

Standard deviation concept is used to measure how far any data is from the mean. One standard deviation from the mean covers 68% of the data. Meaning, if the thickness of the 100,000 tyres are plotted, 68,000 of them lie within one standard deviation above or below the mean.

Standard deviation is also called Sigma. Six sigma means 6 standard deviations from the mean. This would cover 99.999885% of the data.

Now, if a company operates at 6 sigma level, they would ensure that all tyres that are up to 6 standard deviation from the mean are defect free. So, in such cases, one can expect only Three defective Tyre out of two Million tyres manufactured!

POST COMMENT

Ain't no sunshine in Los Angeles A Visit to Marbella What Material Need to Your Ashtanga Yoga Mat Be Manufactured of? Baroque Period Japan earthquake 11 april Manny pacquiao showing up late is disrespectful to freddie roach Manny Pacquiao Will Outpoint Shane Mosley in a Surprisingly Good Scrap How to Properly Calculate Your Bra Size Growing Greener Grass on Your Side of the Fence The Masaai Age-set The Masaai Cultural Beliefs Instant Stability Method Bafflement IFRS: An opportunity or an obstacle?