A systems approach refers to a set of processes, methods and practices that aim to affect systems change. The Organisation for Economic Co-operation and Development (OECD) and the International Institute for Applied Systems Analysis (IIASA) have expertise and experience in applying systems thinking to propose new approaches to achieving the understanding of systemic properties such as tipping points and resilience.

The systems approach provides a methodology to achieve a better understanding of non-linear behaviour of complex systems and improve the assessment of the consequences of policy interventions. They recommend for policy makers to not insist on a single and agreed definition of the problem, to not distinguish facts from values, to not set up a single metric for comparing and assessing options, and to not optimise around the most promising option. The approach should be applied to both the system to be governed and the governance system itself.

The OECD and IIASA could collaborate on aspects such as:
 

• linkages between finance,
• investment and climate change,
• concerted policies for the climate,
• ecosystems, energy and water nexus, among others.

The publication may be of interest to cities and regions that are at the beginning of their circular economy transition and are seeking information about the benefits and importance of the systems approach and its application in the transition to a circular economy, especially in relation to policy making. The paper also presents an overview of practical tools developed by the OECD and IIASA that can support cities and regions in applying a systems approach in practice.