Six Sigma Tutorial -> Defect Based Six Sigma Metrics (DPO, DPMO, PPM and DPU)

DPO, DPMO, PPM, DPU Definitions - Six Sigma Defect Metrics

What Is DPO? What Is DPMO?
 

• Determine all the possible opportunities for problems
• Pare the list down by excluding rare events, grouping similar defect types, and avoiding the trivial
• Define opportunities consistently between different locations
   

Proportion Defective (p):

Yield ( Y_1st-pass or Y_final or RTY)

Y = 1 - p

The Yield proportion can converted to a sigma value using the Z tables
 

Defects Per Unit - DPU, or u in SPC

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
 

Defects Per Opportunity - DPO

DPO = no. of defects / (no. of units X no. of defect opportunities per unit)

Defects Per Million Opportunities (DPMO, or PPM)

DPMO = dpo x 1,000,000

Defects Per Million Opportunities or DPMO can be then converted to sigma & equivalent Cp values (see sigma table)