What is the defect rate for Six sigma?

What is the defect rate for Six sigma? Correct Answer 3.4 defect per million lines of code

Concept:

  • Six Sigma is a statistical term used to measure the number of defects that processes create.
  • The term implies high-quality performance because a process performing at a Six Sigma level allows only 3.4 defects per one million opportunities.

Different sigma levels of quality would lead to the following number of defects.

  1. Three Sigma quality – This level of performance produces a defect-free product 93.32% of the time. 770 applications would be processed incorrectly and would require rework every day.
  2. Four Sigma quality – This level of performance yields a defect-free product 99.349% of the time. With four sigma quality, 73 applications would need to be corrected every day.
  3. Five Sigma quality – Five Sigma performance produces defect-free products and services 99.977% of the time. Every week the bank would need to correct 13 application errors.
  4. Six Sigma quality – Six Sigma performance produces a defect-free product 99.99966% of the time; allowing only 3.4 errors per one million opportunities. 10 applications would need to be corrected during the entire year.

Important Points:

Four sigma and six sigma levels of performance both have an error free rate over 99% of the time. However, the large volume of applications in this example makes all of the difference. With numbers this big, it turned out that the four-sigma process made 18,710 more errors than the six sigma process.

Related Questions

A senior quality engineer during a training session trains his juniors about a particular common defect that has been found in their assembly. He has formulated a plan which will rectify the defect and ensure that the same defect does not pass further to the customers. Which of the following inference is incorrect?
In an experiment you add increasing amount of sigma factor to a mixture of DNA fragment and core polymerase in vitro. You also add ATP and ATP in the mixture and check the rate of incorporation. Results show that the incorporation of both of this labels increase on adding more sigma factor. What will you conclude from your observation?
When a body is subjected to direct tensile stresses ($${\sigma _{\text{x}}}$$ and $${\sigma _{\text{y}}}$$) in two mutually perpendicular directions, accompanied by a simple shear stress $${\tau _{{\text{xy}}}}{\text{,}}$$  then in Mohr's circle method, the circle radius is taken as
When a body is subjected to biaxial stress i.e. direct stresses ($${\sigma _{\text{x}}}$$) and ($${\sigma _{\text{y}}}$$) in two mutually perpendicular planes accompanied by a simple shear stress ($${\tau _{{\text{xy}}}}$$ ), then maximum shear stress is
The pull required to tear off the plate per pitch length is (where p = Pitch of rivets, t = Thickness of plates and $${\sigma _{\text{t}}},\,\tau $$  and $${\sigma _{\text{c}}}$$ = Permissible tensile, shearing and crushing stresses respectively)