BASF is co-operating with Karlsruhe University and the Öko-Institut e.V., Germany, in developing a method for measuring social aspects of sustainability with the aim of incorporating them into BASF's existing eco-efficiency analysis. Whereas numerous instruments are used in practice for the ecological assessment of products and processes, a gap still has to be closed by developing social life-cycle assessment procedures. Based on the principles of the BASF eco-efficiency analysis on the one hand, and a product-related specification of the social sustainability dimension on the other hand, a social life-cycle assessment procedure has been developed which is now to be tested and discussed. The new integrated instrument, the so-called SEEbalance¨, will be applied at BASF in order to improve the performance of the company's product portfolio and manufacturing processes and to market advantageous products. This paper presents the concept of the new methodology. SEEbalance¨ is a comparative life-cycle assessment tool that consists of three main aspects: costs, environmental impact and social effects of different product or process alternatives are examined and compared. Socio-eco-efficient solutions combine a relatively good environmental performance with high social benefit and at the same time low costs for the end customer. Social criteria for the evaluation of products and processes are proposed. The developed method for the social life-cycle assessment is based on an industrial sector analysis of statistical data. The final aggregation and presentation of the results is done in an analogous manner to the eco-efficiency analysis.