The reason CEERIS only counts number of parts and number of solder joints is because it analyzes the PROCESS performances. Adding the number of components to the OFD count is justified when the DPMO analysis also covers component failures. CEERIS takes great care to NOT include defective components identified during the assembly and test into its computation of the process DPMO. By example, the electronic failure of a component is excluded from the CEERIS defect count while an error in test software is a true process defect.
For future DPMO benchmarking research, CEERIS shall adopt the IPC counting method for OFDs. This will not impact the validity of the statistical series previously published by CEERIS in various reports. It will simply allow CEERIS to cover both the material as well as the process quality performances.
If you wish your facility to be part of future DPMO programs sponsored by CEERIS, please contact us at ceeris@aol.com