Abstract:It is necessary to change the current dynamic of growth, to assure that future generations can satisfy their needs. Sustainable development and global sustainability are two concepts that have achieved great importance in almost every sector of activity. There is a wide range of methods and models for sustainability assessment. Nevertheless, it is necessary to go beyond evaluation, looking for sustainability optimization. In spite of this, little work has been done on the latter field. The authors present here a conceptual proposal for an integrated method to optimize sustainability of engineering systems, based on the MIVES (integrated value method for evaluating sustainability) method. For a better understanding of the method, its essential steps for optimizing an energy sub-system are summarized (shell-and-tube heat exchanger).