from a jersey jack factory tour:
at the 11:45 mark, jack comments on his companys pinball playfields:
"so uh our playfields come in these boxes and, you know, they get QCd. if theres anything wrong with them, they get rejected. and really these playfields, um they made by mirco in germany. he does an amazing job. and uh, theres a significant cost to these. but this is your whole game. this is what youre looking at. this is the building block of the game. so if its not done the right way, uh you know your game is kinda worthless."
for those discussing the time required for a playfield swap, at the end of the hobbit assembly line [26:49], jack answers the question "how many hours does it take to make a machine start to finish ?" "it takes about 24 hours, 24 man/woman hours".