Choosing between DPU and DPO can be a bit tricky but as a general rule of thumb DPU is usually used when there is only one performance measurement available. DPO is used when there are more than one available. So how exactly do we calculate DPO? These few steps will help you in obtaining your defects per opportunity measurement.
Step 1 - Assuming you have your total number of measurements or sample batch or lot size figured out already, you will need to gather your team together and brainstorm a list of potential defects that customers might be concerned with. There is not much risk involved in this step but be cautious that you do not repeat "opportunities" as it could skew your data.
Step 2 - Once you have all the opportunities the team can come up with you need to calculate the total number of defect opportunities. This is done by multiplying the number of units in your sample lot or batch by the number of opportunities the team came up with.
Step 3 - Divide the total number of defects in the sample lot or batch by the total opportunities for defects, which was the answer you came up with in step 2. This will give you your DPO.
This number can now be used to calculate your Defects per million opportunities.