Sustainable development' is perceived as a topic of steadily increasing importance. At its core lies a tension between the goals of economic growth and protection of environmental quality. As organizations have a direct impact (e.g., through their production processes) on the sustainability of a society and the planet as a whole, ensuring their sustainable development is crucial. In this paper, we argue that the sustainable development of organizations may be positively inuenced by increasing organizations' awareness of environmental impact of their products. Therefore, to support the assessment of environmental impact of product systems, based on ISO 14040, we design a domain-specic modeling method ImpactM as part of the Multi-perspective Enterprise Modeling (MEMO) approach. We evaluate it against identied requirements as well as using an exemplary scenario.