The need to define strategies and policies useful to pursue sustainability of cities requires a deeper reflection on the role of the maintenance process for urban systems. The attention that is devoted to the subject of care and maintenance is one of the most significant acquisitions of contemporary post-industrial culture increasingly oriented towards sustainability objectives. The attention paid to the themes of curing and maintaining represents one of the most significant acquisitions in post-industrial contemporary culture, more and more oriented towards sustainability objectives. The urban maintenance theme can be considered as a real strategy for the built environment sustainability; indeed, it is the primary tool for knowing and governing the complex and heterogeneous contemporary reality, through which we can achieve the system reliability as well as the sustainability regulating life dimension. This contribution becomes an opportunity for reflecting within the technological culture of maintenance project, whose disciplinary discussion is today based on the application modes of such discipline at a building and an urban scale as well. Indeed, the methods and instruments for programming and maintaining the urban organism – intended as a complex unit system – can’t be those ones used for sub-systems and urban components, but they have to be strategic instruments able to help managers and citizens to “decide how to decide”. It is necessary to reach an integrated approach that, overcoming the logic of a technical management intended as a mere addition of parts, reaches systemic operating modes.