Modular construction (MC) is an innovative approach to enhancing productivity and sustainability, but its complex and dynamic supply chain is challenging. This paper develops and validates a dialectical system framework for understanding and enhancing the MC supply chain, through the combination of a literature review, interviews with 59 professionals and a case study of modular integrated construction development in Hong Kong, China. The developed framework encompasses seven key components of the MC supply chain technical system-namely, pre-approval, building plan pre-submission, detailed design, module production, logistics, module installation, and quality assurance and quality control-considering various stakeholders embedded in broader contexts. The case study validates the framework as a theoretical lens to comprehend the complex MC supply chain and as a novel analytical model to enhance the MC supply chain from different stakeholder and contextual perspectives. Future research directions are suggested regarding strategy establishment, performance measurement and policy road map development to achieve a mature and sustainable supply chain.