This paper draws on the results of a multi-disciplinary research project funded by Defra1 which has focussed on identifying and developing practical approaches by which the dairy sector can reduce inputs and diffuse pollution, whilst maintaining biodiversity, product quality, high animal health and welfare standards and market competitiveness. The pressures on UK dairying for change towards greater economic and environmental sustainability derive from the need to remain profitable in the face of low farm-gate prices, competition from the global market in the context of a wide range of environmental and animal welfare constraints that have increased considerably in number and stringency during recent years. The challenge is to identify and develop practices that, through the use of integrated systems, incorporate environmental objectives into profitable, modern farming. The research has explored the complex interaction 'surfaces' of multiple sustainability criteria in systems simulations using an interactive framework of modelling (N, P, methane and production economics) and objective scoring matrices (biodiversity, landscape features, product quality and animal health). As part of the SIMSDAIRY model2, the EDMM (Economic Dairy Management Model) is an empirically-based model which simulates the revenue and costs attributed to dairy farming in the UK. At its core are a series of econometric relationships that replicate the underlying production and cost structures of dairy farm management. The results are presented and discussed in the context of recent market and policy developments in the milk supply sector.