"Systems Science for Complex Policy Making" offers a comprehensive analysis of the complex dynamics in the political decision-making process, particularly through the example of Indonesia. The book highlights the challenges arising from the country's high heterogeneity, which consists of 1,340 different tribes and 17,508 islands. Each region has its own natural strengths and conditions, leading to interdependence among the regions while simultaneously optimizing their individual circumstances. Although the democratic form of government and high regional autonomy promote individual freedom, they also frequently bring about conflicts of interest and coordination problems. These unique characteristics of Indonesia create a complexity that is rarely found in other countries. The book argues that conventional theories and best practices, based on simplified assumptions, often fall short in addressing these challenges. Instead, a systems science approach is proposed, which takes into account the necessity of intensive interactions and negotiations in public policy and has the potential to overcome these complexities.