Mass production is the production of machinery and other articles in standard sizes in large numbers. Mass production makes it possible to manufacture things faster, and often at less cost. It also means that a replacement can be obtained for any part of a manufacturing machine or other product that breaks down.
In the early 1900's, Henry Ford originated the moving assembly line for manufacturing automobiles. After the automobile parts are made, the automobile frame is attached to a conveyor belt. This belt consists of a chain that moves along the floor of the factory. Workers are stationed along the chain in an assembly line. As the car moves slowly along the line, each worker does a special task. The task must be done in a certain length of time, and with exactness, because the work of the entire line is stopped if it is necessary to halt the moving chain. Mass production led to the division-of-labor system, in which each worker is skilled in a single operation.
Excerpt from the "Mass production" article, The World Book Encyclopedia © 1999