DPMO as applied in this standard is a measurement taken on completed product. Only those defects detected or discovered at an assemblys completed product evaluation are to be included in the calculations. A companion standard, IPC-9261 In-Process DPMO and Estimated Yield for PWAs is used to develop DPMO indices for measuring in-process assembly steps.
It is recognized that a manufacturing index can be obtained through a variety of methods. Overall Manufacturing Index (OMI) is explained in detail in Appendix B.
This document is intended to be used in conjunction with assembly acceptance standards such as IPC/EIA J-STD- 001 or IPC-A-610. This document is for benchmarking and is NOT intended to describe how to track or otherwise log defect types or drive corrective action. In-process DPMO is outside the scope of this document.