In the context of current increasing variety, interconnectivity and alteration, many methods and tools for planning and decision-making such as time series analysis and trend extrapolation do not longer work out. Along the demands for good governance and open government, policy-makers need concise, reliable and up-to-date information to manage society’s problems and affairs in an efficient and effective way. Likewise, stakeholders affected by a particular policy demand transparency, accountability and trustworthiness in political decision-making. Along the increasing digitisation of the Information Society, citizens are more and more requesting direct involvement in policymaking. The implementation of good governance principles as already defined a decade ago by OECD or the European Commission become predominant in societal evolution. In this contribution, a novel approach to policy development through collaborative scenario building via online means and formal modelling and simulation of policy is introduced. The approach adds value to current policy discussions by facilitating the understanding and assessment of specific policy issues, letting stakeholders express their views and concerns on a policy via collaborative scenarios and e-participation tools, and providing means to better understand consequences of policy choices.