Innovations in public policy are difficult to realize if decision-making arrangements are not scrutinized at the same time. Rigid institutional arrangements often hinder the realization of policy breakthroughs. Consequently, in the day-to-day practice of public administration, more and more experiments with innovative arrangements towards realizing groundbreaking policy decisions are being seen. Two rather different examples of such arrangements in the Dutch context are transition arenas and pilot projects (proeftuinen). In this article we describe these arrangements from an innovation management perspective and evaluate their functioning by focusing on their approaches to two dilemmas: the dilemma between diversity and closedness within the innovation plans and the dilemma between openness and closedness of the plan in relation to its context, the outside world. From their comparison we can learn about the context-specific application of different innovation plans and the results of different ways of handling these innovation dilemmas.