To accomplish a Six Sigma level, a production process must generate less than 3.44 defects per 1,000,000 opportunities, as shown in the table below:
The Six Sigma Levels and their corresponding defects
To identify if the capability of the process is relative to the specifications of that process, Process Sigma rating should be computed. To compute for the process sigma rating, we have to determine the total number of defects, total number of opportunities, and defect rate.
How to calculate it yourself… the simple explanation
A defect is anything outside of customer’s requirement. An opportunity on the other hand is the total number of the probability for a failing. Based on the Process Sigma Table, Six Sigma rating should have 99.99966% yield. Yield is the percentage of products or services without defects. That is like one wrong drug prescription in twenty-five years. As a business strategy improved sigma rating results in improved process or product, reduced cost and greater customer satisfaction.

Click to gain access to Six Sigma Calculator excel template for a quick evaluation to determine the total number of defects, total number of opportunities, and defect rate.