sTEm–at-Work: Answer for Puzzle #31

This puzzle provides the opportunity to explore the plots and determine that two of the
three batches of devices have failed quality expectations each for a different reason.  The inverse response dependency is present in one of the failed batches while the other does not exhibit this inverse relationship. This provides opportunities to discuss direct and inverse relationships relative to function response.   The high temperature response of the other two batches provides the distinction between failed performance and expected performance for the two batches that do exhibit inverse response characteristics.  The interesting point to make about Diode lot: PP#203B is the fact that although it has in inverse linear region, the fact that the output voltage value goes up as temperature goes up is a valid reason for rejecting the batch.  This high temperature region response suggests that there was a flaw somewhere in the manufacturing process and thus the devices with that flaw cannot be trusted to perform as expected through their entire life cycle.  The fact that the devices in Diode lot PP#520B fail as expected provides an opportunity to discuss the fact that devices are designed to operate within a desired range.  If the devices operate correctly within that range and do not exhibit unexpected operational characteristics outside that designed range, the devices will pass their quality inspection.

All three batches of these devices have to be reported as not meeting performance expectations?

Answer: NO