Defect Per Unit (DPU) versus DPMO

All depends on the product. I say that because some stuff just isn't worth the effort, you other CM's know what I'm talking about. We do a review on every run after it is complete and there are many actions that can be taken. We always first focus on the top 3 defects then we look for DFM issue and feed that back to the customer. We are generally a high mix operation so it is very difficult to drive defects to 0 but if you alway focus on fixing your top three you can develop some pretty good processes.

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Alot of QM's and QE's are typically failed Engineers who lack common sense. They don't understand that measuring in DPMO's (versus DPU's) "normalizes" your data for Printed Circuit Board Assemblies (PCBA's) so that if you have 10 defects on a PCBA that has 100 opportunities versus 10 defects on a PCBA that has 100,000 opportunities, you'll still be comparing apples to apples.... Sure DPU may work for other things, but the QM's and QE's don't get it.

IPC7912 & IPC9621 are the industry standards for how DPMO is calculated.

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