This session will review the state of the art and science of measuring progress towards sustainability. As we move down the path of sustainability implementation, providing the products and services required by society with progressively less negative impact on the earth, quantification of these improvements is essential. It is the intension that this session will set the ground works, so that over time, the import of metrics used in one discipline to another will occur so that a comprehensive set of metrics can be developed and used by all for a chosen system.