Continuous flow production

Mass production (also called flow production, repetitive flow production, or series production) is the production of large amounts of standardized products on production lines.It was popularized by Henry Ford in the early 20th Century, notably in his Ford Model T. Mass production typically uses moving tracks or conveyor belts to move partially complete products to workers, who perform simple repetitive tasks to permit very high rates of production per worker, allowing the high-volume manufacture of inexpensive finished goods. Mass production is capital intensive, as it uses a high proportion of machinery in relation to workers. With fewer labour costs and a faster rate of production, capital is increased while expenditure is decreased. However the machinery that is needed to set up a mass production line is so expensive that there must be some assurance that the product is to be successful so the company can get a return on its investment. Machinery for mass production such as robots and machine presses have high installation costs as well. Thus, mass production is ideally suited to serve large, relatively homogenous populations of consumers, whose demand would satisfy the long production runs required by this method of manufacturing. As such, it is not surprising that, given a number of other factors, mass production first became prevalent in the United States.
See more at Wikipedia.org...

Means that items are produced and moved from one processing step to the next one piece at a time. Each process makes only the one piece that the next process needs, and the transfer batch size is one.