The Mars company historically were big on automation and vending machines, in the pre-computer era Mars were the big player in this business. I think that a lot of that expertise must have been gained on the factory production hardware before the other business came along, i.e. the vending machines and the global export opportunities for such hardware, able to do such things as reliably dispense a packet of crisps.

Once Mars and co mastered the art of automation then anything became possible. I think this was a different thing to 'mass production' as that had gone on for a long time before Ford in UK food manufacturing, e.g. biscuits in Reading.