This article points out the basic concept of „One-Piece-Flow” in the context of facility planning in manufacturing and shows examples of its successful application in assembly. The authors present configuration variants of this concept and they show the important design parameters with their effects on the system performance. While in the 80’s the principle of flow production was used only for large scale production and mass production, there is a new understanding today: the flow principle is also usable with advantages for medium quantity production, especially for assembly operations carried out by manual and by automatic work stations as well.