Assembly Line

An assembly line is a manufacturing process (most of the time called a progressive assembly) in which parts (usually interchangeable parts) are added to a product in a sequential manner to create a finished product much faster than with handcrafting-type methods. The division of labour was initially discussed by Adam Smith, regarding the manufacture of pins, in his book The Wealth of Nations (published in 1776). The assembly line was first mechanized in the U.S. by Eli Whitney, who also patented a type of cotton gin. Whitney began using the assembly line to manufacture muskets that had interchangeable parts. In 1797, he was contracted to supply 10,000 muskets for the U.S. government in two years.

Prior to Whtiney's mechanization of the assembly line, craftsmen made muskets one at a time. Due to the handmade & custom nature of this process, each musket was unique. If a single part of the musket broke, it could not be easily replaced, but instead required a custom repair. Because parts manufactured by Whitney's assembly line parts were interchangeable, common parts could be used to replace broken ones. This was a vast improvement in both manufacturing and maintenance of produced goods. In the early 1900s, Ford Motor Company adopted the assembly line to mass produce the Model T.