Background: There has been a renewed interest in broadening the research agenda in health promotion to include action on the structural determinants of health, including a focus on the implementation of Health in All Policies (HiAP). Governments that use HiAP face the challenge of instituting governance structures and processes to facilitate policy coordination in an evidence-informed manner. Due to the complexity of government institutions and the policy process, systems theory has been proposed as a tool for evaluating the implementation of HiAP. Methods: Our multiple case study research programme (HiAP Analysis using Realist Methods On International Case Studies -HARMONICS) has relied on systems theory and realist methods to make sense of how and why the practices of policy-makers (including politicians and civil servants) from specific institutional environments (policy sectors) has either facilitated or hindered the implementation of HiAP. Herein, we present a systems framework for the implementation of HiAP based on our experience and empirical findings in studying this process. Results: We describe a system of 14 components within three subsystems of government. Subsystems include the executive (heads of state and their appointed political elites), intersectoral (the milieu of policy-makers and experts working with governance structures related to HiAP) and intrasectoral (policy-makers within policy sectors). Here, HiAP implementation is a process involving interactions between subsystems and their components that leads to the emergence of implementation outcomes, as well as effects on the system components themselves. We also describe the influence of extra-governmental systems, including (but not limited to) the academic sector, third sector, private sector and intergovernmental sector. Finally, we present a case study that applies this framework to understand the implementation of HiAP -the Health 2015 Strategy -in Finland, from 2001 onward. Conclusions: This framework is useful for helping to explain how, why and under what circumstances HiAP has been successfully and unsuccessfully implemented in a sustainable manner. It serves as a tool for researchers to study this process, and for policy-makers and other public health actors to manage this process.

Health in All Policies (HiAP) is a strategy that seeks to integrate health considerations into the development, implementation and evaluation of policies across various non-health sectors of the government. Over the past 15 years, there has been an increase in the uptake of HiAP by local, regional and national governments. Despite the growing popularity of this approach, most existing literature on HiAP implementation remains descriptive rather than explanatory in its orientation. Moreover, prior research has focused on the more technical aspects of the implementation process. Thus, studies that aim to 'build capacity to promote, implement and evaluate HiAP' abound. Conversely, there is little emphasis on the political aspects of HiAP implementation. Neglecting the role of politics in shaping the use of HiAP is problematic, since health and the strategies by which it is promoted are partially political.This glossary addresses the politics gap in the existing literature by drawing on theoretical concepts from political, policy, and public health sciences to articulate a framework for studying how political mechanisms influence HiAP implementation. To this end, the glossary forms part of an on-going multiple explanatory case study of HiAP implementation, HARMONICS (HiAP Analysis using Realist Methods on International Case Studies, harmonics-hiap.ca), and is meant to expand on a previously published glossary addressing the topic of HiAP implementation more broadly. Collectively, these glossaries offer a conceptual toolkit for understanding how politics explains implementation outcomes of HiAP.