History Of Six Sigma

Let’s see the History of Six Sigma. Sigma" is a letter of the Greek alphabet and is used in statistics as a measure of variation. Joining customer specifications and variation provides the method to evaluate defects per million opportunities (DPMO) that translate into capability index Z. Customer input will determine the goal and improvement required for mission-critical processes. Products and business processes at successful corporations worldwide typically operate at 3-3.5 Sigma, which implies a DPMO of 67,000 and 23,000 respectively.

Per History of Six Sigma, the roots of Six Sigma as a measurement standard can be traced back to Carl Frederick Gauss (1777-1855) who introduced the concept of the normal curve. Six Sigma as a measurement standard in product variation can be traced back to the 1920's when Walter Shewhart showed that three sigma from the mean is the point where a process requires correction. Many measurement standards (Cpk, Zero Defects, etc.) later came on the scene but credit for coining the term "Six Sigma" goes to a Motorola engineer named Bill Smith. (Incidentally, "Six Sigma" is a federally registered trademark of Motorola).

According to History of Six Sigma, in the early and mid-1980s with Chairman Bob Galvin at the helm, Motorola engineers decided that the traditional quality levels -- measuring defects in thousands of opportunities -- didn't provide enough granularity. Instead, they wanted to measure the defects per million opportunities. Motorola developed this new standard and created the methodology and needed cultural change associated with it. Six Sigma helped Motorola realize powerful bottom-line results in their organization - in fact, they documented more than $16 Billion in savings as a result of our Six Sigma efforts.

Since then, hundreds of companies around the world have adopted Six Sigma as a way of doing business. This is a direct result of many of America's leaders openly praising the benefits of Six Sigma. Leaders such as Larry Bossidy of Allied Signal (now Honeywell), and Jack Welch of General Electric Company. Rumor has it that Larry and Jack were playing golf one day and Jack bet Larry that he could implement Six Sigma faster and with greater results at GE than Larry did at Allied Signal. The results speak for themselves. Six Sigma has evolved over time. It's more than just a quality system like TQM or ISO.

History of Six Sigma: Six Sigma can be defined in a number of ways. As a measurement standard, its roots can be traced back to Carl Frederick Gauss (1777-1885) who introduced the concept of the normal distribution curve.  As a measurement standard in product variation, Six Sigma began in the 1920’s, when Walter Shewhart showed that three sigma (or standard deviation) from the mean is the point where a process requires correction.  Motorola coined the actual term “Six Sigma” in the 1980’s from their need to develop a new standard for measuring process variability and defects.  From this standard came the methodology and needed cultural change associated with it that we see so often today in Six Sigma deployments.

Since then, hundreds of companies around the world have embraced Six Sigma as not just a quality initiative but as a way of doing business.  Surprisingly, the drivers have been many of America’s business leaders such as Larry Bossidy of Allied Signal (now Honeywell) and Jack Welch of General Electric Company. Today, Six Sigma can be described as: a vision; a philosophy; a symbol; a metric; a goal; a methodology.  

In it’s most tactical form, Six Sigma is a metric.  It represents 3.4 defects per million opportunities (DPMO) within a single process.  This concept will be covered in more detail later in our discussion.  At the most strategic level, Six Sigma is a management strategy that offers a system for managing the total business enterprise. When done well, Six Sigma offers a toolkit for increasing the business financial performance, market share, service/product quality, and customer satisfaction and employee satisfaction/empowerment.   From my perspective as a practitioner, Six Sigma is about four basic themes:

• Reducing variability and the defects in your business processes...fixing the problem.
• Focusing on measuring and controlling the component variables that are INPUT as opposed to the process result or OUTPUT.  
• Aligning your business process with the real requirements of your customer.
• Creating standard and valid metrics to continuously measure the improved process so you can sustain the gains.