Agricultural technologies and agricultural, environmental and rural development policies are increasingly designed to contribute to the sustainability of cropping and farming systems and to enhance their contributions to sustainable development at large. The effectiveness and efficiency of such policies and technological developments in realizing desired impacts could be greatly enhanced if the quality oftheir ex-ante assessments were improved. Four key challenges and requirements to make research tools more useful for integrated assessment in the European Union have been defined (Van I.ttersum et al., 2008): (a) overcome the gap between micro-macro level analysis, (b) decrease the bias in integrated assessments towards either economic or environmental issues, (c) ensure reusability of models and their use for indicator assessment and (d) overcome hindrances in technical linkage of models. Tools for: integrated assessment must have multi-scale capabilities and preferably allow application to a broad variety of policy questions. At the same time, to be useful for scientists, the framework must facilitate state-of-the-art science both on aspects of the agricultural systems and on integration. This paper presents the design of a framework for agricultural systems (SEAMLESS Integrated Fratnework) and discusses the implications for cropping and farming systems modelling.