A unit of product can be defective if it contains one or more defects. A unit of product can have more than one opportunity to have a defect.
p = Number Of Defective Units / Total Number of Product Units
Y = 1 – p The Yield proportion can converted to a sigma value using the Z tables
DPU = Number Of Defects / 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.
DPO = no. of defects / (no. of units X no. of defect opportunities per unit)
DPMO = dpo x 1,000,000 Defects Per Million Opportunities or DPMO can be then converted to sigma & equivalent Cp values in the next page. The DPMO, DPM, Sample Size, CI Calculator will help you calculate the metrics.
If there are 9 defects among 150 invoices, and there are 8 opportunities for errors for every invoice, what is the dpmo? dpu = no. of defects / total no. of product units = 9/150 = .06 dpu dpo = no. of defects / (no. of units X no. of defect opportunities per unit) = 9/(150 X 8) = .0075 dpo dmpo = dpo x 1,000,000 = .0075 X 1,000,000 = 7,500 dpmo What are the equivalent Sigma and CP values? See Sigma Table.
Given: a proportion defective of 1%
This six sigma conversion table converts yield to dpmo, sigma, copq etc.
|Yield||dpmo||Sigma (σ)||Cp Equiv.||COPQ (Cost of Poor Quality)|
DPMO, DPM, Sample Size, CI Calculator will help you calculate the metrics.