One Piece Flow, single piece flow or continuous flow manufacturing are terms used to describe the technique used to manufacture components in a cellular environment. The principle is that no single unit of production can move to the next downstream section in the production cell until that person completes their process step. As a result this means that if necessary the entire process cell should wait until the downstream process is completed because the goals of one-piece flow are to make one part at a time, every time, and defect free.