That's really interesting. Whose job is it to actually design and develop the prototype board? It seems like that team would have to know quite a bit, if not nearly everything, about the device.
Usually the design engineer that handles the production board goes through the EVT boards.
Basically the purpose of EVT to a) ensure all the components identified in the initial survey/design review actually work together b) enable software development early in the process c) iron out any showstoppers and kinks that could jeopardize the project later on.
The next few design stages usually get rid of all the super-debug stuff (such as the ethernet port on the iphone; also maybe get the form factor down) while still retaining the regular debug stuff (JTAG etc). This usually when mechanical can jump in and preliminary compliance stuff can take place (EMC etc)
Basically the purpose of EVT to a) ensure all the components identified in the initial survey/design review actually work together b) enable software development early in the process c) iron out any showstoppers and kinks that could jeopardize the project later on.
The next few design stages usually get rid of all the super-debug stuff (such as the ethernet port on the iphone; also maybe get the form factor down) while still retaining the regular debug stuff (JTAG etc). This usually when mechanical can jump in and preliminary compliance stuff can take place (EMC etc)