To summarize the approach to sustainability in a few words: The work of Aubin and his successors on the mathematical theory of sustainability (Aubin 1991, Aubin et al, 2012) has inspired numerous studies on sustainable management and optimal control, particularly at INRAE. The approaches studied within the network focus on the trade-off between dynamics and constraints without directly seeking an optimal solution (initially), unlike traditional approaches to optimal control theory. The advantage of this approach is that it does not impose a trade-off between short-term and long-term considerations, or between different aspects of sustainability.