I am an electrical engineer with a very well known company that designs electrical hardware (controllers, sensors/switches, etc). That said, all of our major parts are expected to last the life of the vehicle without failure under normal conditions. Ford electrical engineering dropped the ball when it came to the PCM controller. I have 94k miles on the car and the controller failed for no reason other than to just crap out. Control modules shouldn't fail for normal system operation or emergent behavior. Why wasn't this caught in the numerous design reviews or performance/reliability testing? 2 of my 3 vehicles are Fords, I can't say that my next is going to be. This was easily preventable.
All wheel drive
Powertrain control module I/O response to voltage transients, over voltage, under voltage, short to ground, short to battery, open circuit, intermittent shorts/opens, A/C coupling from adjacent circuits/plug coils, EMI susceptibility, and reverse polaity would be a start for all I/O. I would specifically test the plug coil I/O for failure conditions when the coil is about to open or short. Determine the voltage spike/transient levels that are causing the PCM output FETs to blow and protect against it. This is a big black eye for Ford given the vehicle movement towards more electronic control. Makes me question their more involved electrical systems, like on the hybrids.