The assembly line was a gradual innovation, we can't even point to an inventor
Henry Ford defined the goals--faster production, lower price--for which the assembly line was the best answer
water power

the assembly line wasn't widely used earlier because it didn't work with the layout of steam powered factories

in 1910 18.7% of factory power came from electric motors, up from 3.6% in 1900 (p. 18)

an early Model T had 10,000 parts

1910 Highland Park factory
            Park factory

flexible factory floor with machines with individual electric motors
intensive subdivision of work
then the idea of moving the car in 1913model T production

key features:

fundamentally Ford is struggling to come up with ways to make cars faster to keep up with demand--this led his engineers to put existing pieces together so they add up to make a huge difference

no one invented the assembly line earlier because no one had the need to make something that complex that fast--Ford's big invention was a car design (the Model T) that hit the sweet spot of what the public wanted

the assembly line makes production so much more efficient that Ford can

Paying workers $5 a day
eliminating waste

Taylorism vs. Fordism