A system of industrial production involving the manufacture of a product or part in large quantities at comparatively low unit cost. It was in the car industry, initially in the US Ford Company in 1913, that the age of mass production was fully inaugurated. Standardized parts were brought together on a moving assembly line to turn out standardized cars at low cost, but with high wages and profits. At the same time, time-and-motion studies were undertaken to analyse and improve efficiency. Mass production methods thereafter were steadily introduced into other areas of manufacturing, for example in World War II in shipbuilding and aircraft manufacture.

Until recently, the high degree of mechanization and automation involved in mass production required the standardization of both the product and the raw materials used in its manufacture. However, the development of versatile manufacturing systems for product monitoring and control has led to improved flexibility. The development of mass-production methods for high-quality items, in particular electronic devices, has led to a shift in emphasis from quality control, in which sub-standard or damaged products are rejected at the end of the production process to quality assurance, in which the whole production process is designed to ensure that the products are of a high standard.