for Acea SpA, Acea Produzione SpA, Acea Ambiente SpA, Acea ATO waste-to-energy plant of Terni (Acea Ambiente SpA), which were selected on the basis of their activities, their contribution to the performance indicators at a consolidated level and their location, we carried out site visits during which we met local management and gathered supporting documentation regarding the correct application of the procedures and calculation methods used for the key performance indicators.