Eli5: On a production line, how do they make a car, plane or anything else be identical from one another without differences?

Question

Eli5: On a production line, how do they make a car, plane or anything else be identical from one another without differences?

In: 6

Answer 1

I am in the automation business.
The assembly lines are automated to create each item repetitively and within very tight tolerances. Its actually rare that items (here in the US) are ‘hand built’. The machines are intelligent enough to reject any part during any process so that the bad parts/assemblies don’t make it to market. An assembly line can assemble a V8 engine every 70 seconds with less then 10 people on that line.