Once in place and scrutinized, the demonstration line showed the need for further adjustments. Some assembly stages took longer than expected so parts supply rates along the line were changed. Entire sub-assemblies of such components as radiators, dashboards, and steering mechanisms were set up so that they could be incorporated in the main line production.
The moving assembly line plan was developed over a five year period and finally put into operation when the new Highland Park, Michigan, factory was opened by Ford in 1913. There a fully-synchronized, power-driven line began with engine assembly on the fourth floor and ended on the ground floor with the body being attached to the chassis. Workers at each station handled one specific repetitive step contributing a small part of the eventual whole. In time, Ford integrated the entire process with the raw materialscoal fuel, ore, and woodentering the plant and the finished automobiles coming out. By 1914, the entire assembly process took 93 minutes.
From 1908 through 1927, more than 15 million Model Ts were manufactured and their price declined from $850 to $300. Ford dealerships were set up throughout the United States and in Europe, Ford Motor Company was an outstanding success and the assembly line principle spread to countless manufacturing operations.
James S. Rogers letter, to Benjamin Franklin, Describing reasons for amending the final report to refocus on the scientific aspect of Ford's achievements, 2/01/1928 (3.5M)
Benjamin Franklin letter, to George A. Hoadley, Referring to a conviction that Ford's qualifications went beyond invention, 2/13/1928 (884k)