Answer:
[tex]11,373 PPM[/tex]
Step-by-step explanation:
The following formula is used to compute the Proportion of error-free units given the sigma level in Excel.
The proportion of error-free units = NORMSDIST(Sigma Level - 1.5)
Suppose that a process is currently operating at a 3.5-sigma quality level.
The proportion of error-free units for this process is
NORMSDIST(3.5 - 1.5) = 0.977250
Therefore, the rejection rate is equal to
[tex]1 - 0.977250 = 0.022750[/tex]
or 22750 PPM.
Now, consider a 6-sigma level process.
The proportion of error-free units equals
NORMSDIST(6.0 - 1.5) = 0.9999966
and the rejection rate is
[tex]1 - 0.9999966 = 3.4 PPM[/tex]
Hence, reduction is PPM required per year , that is
[tex]\dfrac{22750 - 3.4}{2} = 11,373 PPM[/tex]
reduction per year
