The purpose of this study is to analyse and prove the impact of regulatory effectiveness on the supply chain and its impact on sustainable competitive advantage for rice milling companies in Indonesia. The research method used was a quantitative analysis, employing a sample of 200 rice milling companies in East Java. The results of this research indicate that regulations do not have a significant effect on the supply chain, Regulations do not have a substantial effect on sustainability Competitive Advantage, Supply chain has a significant impact on sustainable competitive advantage, in addition, flexibility management can moderate the relationship between the supply chain and sustainable competitive advantage, but flexibility management is not able to moderate the regulatory relationship with sustainable competitive advantage.