production line 
noun
An arrangement in a factory in which a thing being manufactured is passed through a set linear sequence of mechanical or manual operations: we have installed new production lines the first aircraft will be coming off the production line early next year she works on the production line...
- Marie had worked on a factory production line before she became unemployed.
- Workers are not only encouraged to suggest improvements, they can stop the production line if they are not satisfied with quality.
- The production line in his sportswear factory is humming away in the background, churning out the latest in handball kit.