A big challenge for Organic PhotoVoltaic (OPV) production is to succeed in the industrial scale-up, from lab < 0,1cm² cells to Roll to roll > 100cm² modules. OPV materials and performances have seen huge progress over the past 2 years, related to the breakthrough of non-fullerene acceptors and new high-performance donor polymers. Today, academic researchers publish efficiency for lab devices over 17%. But these performances are achieved in very specific environmental and processing conditions, and for extremely small areas of OPV cells One of the biggest challenge for OPV industrials today is to succeed in transferring these materials from lab cell to industrial modules, and limiting the efficiency losses linked to the scale-up. In Armor production lines, we observe a loss of around 50% from lab cells efficiency to stabilized commercial module efficiency. I will present the analysis of the origin of these impressive losses in performances for different OPV structures, based on fullerene and non-fullerene acceptors. The impact of environment, such as oxygen, light or humidity will be assessed, as well as the influence of processing conditions. We will see that an annealing step under Nitrogen can boost OPV performances for some materials, whereas the same annealing step in air completely deteriorates cells efficiency. Relative humidity in the coating room can have major impact on ETL roughness and cause direct performance decrease over time. Roots of degradation of performances form lab to fab, impact of environmental and processing conditions on performances and stability at module scale, and effects of the cell size and interconnects will be presented. Ways for improvements and associated characterization means and techniques will be addressed.