This report describes the development methodology of a Resilience Index (RI) for the operations of the mussel farming in the Ría de Arousa (Arousa Estuary) in Galicia. This index, developed by the REDE research group from the University of Vigo in the framework of TransformAr project, aims to guide stakeholders' behavioural change and provide policymakers and value chain actors with strategic insights to adapt mussel farming operations to extreme climate change effects. The RI has also potential applications in other sectors and regions facing similar challenges. By promoting behavioural change and adaptation measures, the aim is to mitigate operational risks and enhance the resilience of vulnerable communities and industries across Europe. This set of documents includes a report describing the methodology for the development and calculation of the resilience index, as well as the questionnaires for experts and sector stakeholders on risk scenarios, resilience factors, resilience performance of the sector, as well as the anonymised datasets obtained from these questionnaires.