Connected with the French ECOSD networkIn the context of a circular economy, recycling presents as an interesting solution to reduce the impact of raw materials extraction and to reduce the quantity of waste that is incinerated or landfilled. However nowadays, there is no global and complete definition (which could be used as a common reference) of recycling chains. Listing the parameters to be taken into account, such a definition would allow manufacturers and researchers to better assess the efficiency and the stability of supply chains (not only at the beginning of the product lifecycle, but also towards the next one), and to accurately compare them. Therefore, we need a better definition of recycling chains, describing the system in its whole dimension (i.e. all internal and external factors) so as to improve (i) our understanding of the system and (ii) its inherent problems. Firstly, the recycling chain will be defined and described as exhaustively as possible. Then, the second part will focus on the best way to integrate this information when analyzing and optimizing recycling chains. Lastly, perspectives of this preliminary work will be detailed.ADEME, ECOS