Purpose Modular integrated construction (MiC) reengineers the traditional construction process. By introducing factory production and onsite assembly (OA) of modules, MiC reinvents construction projects' uncertainties and risk profiles. The OA stage constitutes the highest end of the MiC delivery and supply chains, where several inherited and symbiotic errors and risk events become realities, negatively impacting the MiC project's success. This study explored the severities of OA risk factors for MiC projects. Design/methodology/approach A comprehensive literature review, consultation of experts and a questionnaire survey of domain experts were conducted to assess the severity of fifteen OA risk factors for MiC projects. The risk severity index was used to compute and rank the severities of critical OA risk factors for MiC projects, followed by proposed mitigation strategies. Findings The study revealed that the top five OA risk factors with the severest impact on MiC projects include modules installation discrepancies and errors, poor cooperation among critical onsite stakeholders, a mismatch between production schedules and site conditions, improper lifting equipment selection for onsite installation and site-fit rework due to discrepancies in drawings. Originality/value This study is the first to offer some important insights into the uncertainties that could compromise the OA objectives of MiC projects. It discussed risk management strategies for known and unknown OA risks and made a unique contribution to the theory, practice, and praxis of MiC supply chain risk management. |