To tackle sustainable development problems, the design of innovative cropping systems cannot rely only on a biophysical analysis at the field level. It requires multicriteria approaches based on biophysical process, economic decision and resource endowments at farm level. In Europe or US, state and federal policies must also be considered in the design process. Bringing these socio-economic aspects into the process of cropping systems design and assessment requires to use multiscale approaches covering hierarchical scales such as the field, farm and region. The SEAMLESS-IF modelling platform, offers a unique opportunity to combine these various scales and to assess how agricultural or environmental policies, together with technological innovations, may affect the sustainability of farming systems and their contribution to sustainable development at higher scales. SEAMLESS-IF allows to combine a set of components (crop model - agro-management data base - farm model - farm typology - territorial typologies) in order to derive environmental, economic and social indicators at various scales (field, farm, landscape, vulnerable zone, region). The SeamFrame software architecture, part of the SEAMLESS-IF platform, allows to link these components and to run simulations of scenarios combining policy changes and agroecological innovations. In this presentation we will show how SEAMLESS-IF has been used in a french region (Midi Pyrenees) to assess policy scenarios combining (i) the Common Agricultural Policy reform (economic driver), (ii) the Nitrate Directive (environmental driver) and (iii) agro-ecological management options such as integrated nutrient management, conservation agriculture or organic farming. Potentials and limits of the framework for research and decision support on cropping systems design are discussed.