The importance of chains and networks for production planning is argued. The concept of `chains and networks¿ is discussed, and it is shown that this label is particularly useful if it captures not only logistics between the nodes of the network, but also institutional structure, information exchange and mutual relations. All of these, and especially their interrelationships, are relevant to the functioning of chains and networks. To learn about the practice of chains and networks, simulation gaming is presented as a suitable means. The nine contributions to this topic that are assembled in this volume are then briefly presented.