Abstract
This study represents an empirical, comprehensive investigation of two different inter-organisational collaborative approaches, offering a novel perspective on collaborative circular business models in the modern economy. In this vein, we explore how open innovation strategies foster the implementation of circular economy practices within a circular supply chain and a circular ecosystem. In addition, we identify and characterise stakeholders' roles in facilitating the translation of circular principles into a viable business. An inductive theorising approach was employed, leveraging an explorative multiple case study methodology. Data were collected from 13 organisations involved in two collaborative networks, designed to establish upcycling practices to recover waste from the food and beverage industry. A critical realist philosophical positioning underpinned researchers' data collection and analysis. As a result, we outline the nature of two different collaborative approaches to pursue a regenerative production system through open innovation strategies: a circular supply chain and a circular ecosystem architecture. The characterisation of the coordinator and orchestrator of collaborative circular business models is also highlighted in our findings. In sum, this study contributes to the literature on circular economy by unveiling the role of open innovation in fostering circular business development. From a practical standpoint, it offers insights for managers of sustainability-oriented companies willing to implement upcycling practices.