The popularized factory method in automobiles is called ‘just-in-time production'.
a jit system means all the parts for an item are brought to the workstation just in time to facilitate production of that one part. this eliminates costly and space-consuming inventory while also reducing warehousing needs, distribution lead time, and cycle times. it's a nightmarish way of running a factory resulting in problems like quality control (see this article on toyota quality control), but it can produce unbelievable quantities of cars.
