**Preface to "Circular Use of Resources"**

In circular economic theories, the primary goal is not to create cycles of material and energy flows (these are already known), but to transform business processes into sustainable, closed-loop resource systems. As long as the basic mechanisms of business models and business innovation planning do not support circular operating principles, material and energy flows cannot be operated in closed cycles. Unfortunately, the appropriate scientific foundations, relevant research background, necessary and credible databases, and connecting scientific analysis are not yet an active part of the linear–circular transformation processes. Typically, in circular economic models, economic actors and members of the supply chain integrate their resources with each other so that business ecosystems can constantly redesign themselves, i.e., operate dynamically and potentially in self-regulatory systems. In traditional supply chains, i.e., according to the linear business model, permanent roles are assigned, while in the cyclical model, we can talk about developing dynamic and potentially independent actors who work together to create circular value flows. The phenomenon can be visualized in a similar way as the form of the Archimedes spiral in which each circle always remains a circle but moves to an ever higher level on its scale of values. Thus, in the circular economy, we no longer talk about value chains, but circular value chains, because these value ranges cover the full spectrum of activities performed by different actors: a product or a service is not only delivered to the user, but its residues (material and energy) are also returned to the system. The different values and innovative elements are shared by the actors of each value group, so the existence of a wide-ranging system of relations and cooperation becomes especially important. Such a degree of cooperation requires digital decision support or the active use of data analysis technology systems.

> **Csaba Fogarassy, J ´ozsef Popp, David Christian Finger** *Editors*
