Six Sigma is a structured and disciplined process which is designed to deliver product and services which are perfect on a constant basis. Six Sigma means at many organizations are simply means a measure of quality that strives for near perfection.
Six Sigma is associated with process capabilities of greater than 1.5, which is called ‘World class Performance’. Sigma is statistical terms which connotes with standard deviation of process measured about its mean.
Six Sigma refers to the number of sigma measured under a process as the variation close to the larger is such that out of one million only 3.4 outputs are defects under the supposition that the process average may drift over the long term.. Two of different theorist it was stated as following:
• Tomkins (1997) – Six Sigma is a program that is aimed at the near elimination of defects from every product, process and transaction.
• Harry (1998) – Six Sigma is strategic Plan to Strengthen profitability, increase market share and raises customer satisfaction level through statistical tools that maylead to quantum gains in quality. Six sigma focuses in eliminating process variation and increasing process control level, while lean drives out non value added activities/waste and promote work standardization.
2. What is meant by defect?
Before we go ahead, lets define two terms:
• A Six Sigma defect is defined as anything outside of customer specifications.
• A Six Sigma opportunity is the total quantity of chances for a defect.
Here are various formulae to measure different metrics related to Six Sigma Defects
Defects per Unit - DPU Total Number of Defects
DPU = ------------------------ Total number of Product Units
The probability of getting 'r' defects in a sample having a given dpu rate can be predicted with the Poisson distribution.
Total Opportunities - TO
TO = Total number of Product Units x