Ransom Olds began mass assembly line production of inexpensive automobiles in 1901 at its Oldsmobile factory in Lansing, Michigan, building on Marc Isambard Brunel’s stationary assembly line innovations in 1802 at Brock Mills, Portsmouth, England. Thomas Blanchard established the assembly line at the Springfield Armory in Springfield, Massachusetts, USA in 1821, an assembly line method of mass production using interchangeable parts.  Henry Ford expanded on this idea further, building the first moving assembly line for automobiles beginning in 1913 at Ford’s Highland Park plant.
Ford vehicles roll off the assembly line every 15 minutes, much faster than previous technology. This increased output eightfold while requiring less labor (12.5 man-hours instead of 1 hour33).
Its dominance in the automotive industry saw the founding of Ford France and Ford Great Britain in 1911, Ford Denmark in 1923 and Ford Germany in 1925. Citroen was the first local European company to adopt this production system in 1921. Assembly lines quickly became a necessity. For companies, they would otherwise have risked bankruptcy; by 1930, 250 such businesses had disappeared. 
Thanks in part to hundreds of small manufacturers vying for the world’s attention, automotive technology moves fast. The electric self-starter and electric ignition, independent suspension and four-wheel brakes invented by Charles Kettering for the Cadillac Motor Company in 1910-1911 were significant advances.
Almost all cars have been mass produced since the 1920s to meet consumer demand, so marketing strategies