This International Standard describes the principles, requirements and guidelines for eco-effciency assessment for product systems, including:a) the goal and scope defnition of the eco-effciency assessment;b) the environmental assessment;c) the product system value assessment;d) the quantifcation of eco-effciency;e) interpretation (including quality assurance);f) reporting;g) critical review of the eco-effciency assessment.Requirements, recommendations and guidelines for specifc choices of categories of environmental impact and values are not included. The intended application of the eco-effciency assessment is considered during the goal and scope defnition phase, but the actual use of the results is outside the scope of this International Standard.