The eleventh principle of systems science states that systems can be understood. When we understand a system, it means that we can make good predictions or useful projections about the system’s behavior. If the mental model we hold of a system correlates well with the relevant features of that system in the real world, our predictions will be accurate. If it isn’t, then the model can be refined and improved or abandoned if necessary. Understanding a system allows us to function successfully through the guidance of accurate models.