The author asserts that the SDGs and the Post-2015 Development Agenda will need to improve on the monitoring and assessment systems of the Millennium Development Goals system if they are to have a significant effect. The author emphasizes that the cross-issue focus of the SDGs and the need to make the SDGs key planning tools for actors at local, national, and international levels both require systems of assessment and revision of rules to improve outcomes. In the tense political context of international development systems, the author argues, chances for a centralized and firmly coordinated system of monitoring, assessment and revision are unlikely and is not currently being developed in the SDG and Post-2015 discussions. To augment such a system, the author argues that those supporting the SDGs will need to develop decentralized systems which are perceived as legitimate to different sets of actors.