The complex co-evolutionary systems approach (CCeSA) provides a framework to study man-made systems. By studying such entities as self-generated, hierarchical, complex co-evolutionary systems (CCeSs), one can investigate the interconnections between their components, along with their relationships with other systems, in order to understand sustainability as an emergent property. A sustainable CCeS is one that exhibits both enough fitness to achieve its multiple, dynamic, constrained, semi-structured, and often incommensurable and conflicting purposes and objectives while performing above threshold values for failure, and enough flexibility to co-evolve with its changing biophysical and socioeconomic environment. Hence, achieving sustainable CCeSs is a semi-structured, constrained, multi-objective, and dynamic optimization management problem with an intractable phase space. Such problems can be solved with the help of a Co-Evolutionary Navigator, which enhances the manager''s decision-making process and co-evolutionary skills, through an increased understanding of the coevolutionary processes among his system, his mental models, and the discovery of new, improved sets of heuristics.