1. auto parts (QS9000)
2. populated mother boards for contract manufacturing (consumer and commercial)
3. printers (consumer and commercial)

I have been in every phase including product marketing and materials manager.

Test units are made differently and do not go through the same mass production cycle time rates. The SPC process is also different. Actual mass production parameters are not set until prototypes are verified and just before mass-production "green light" to begin shipping. This is to reduce inventory and to not procure components that may change in the final build revision.

I did not say the prototypes were "better", just developed under different conditions that may result in "different issues". added: Even the 300 from last month could be different due to FW and new things added may have created new issues. Maybe.