This publication is designed to help companies set targets and monitor the progress of their sustainability performance year on year. It aims to provide a coherent set of measures to assess the impact of industrial activity. The publication introduces a set of indicators that can be used to measure sustainability performance of an operating unit, such as a process plant, a group of plants, part of a supply chain, a whole supply chain, a utility or other process system. The format recommended is consistent with the framework set forth by the Global Reporting Initiative.