Occupational Health and Safety Governance in Internal Outsourcing: A Systematic Review and an Integrative Sociotechnical Framework

Internal outsourcing has intensified organizational fragmentation and redistributed responsibilities for Occupational Health and Safety (OHS) across multiple employers, challenging conventional safety management approaches. This study aims to critically synthesize recent academic research on OHS governance in internal outsourcing arrangements and to develop an integrative explanatory framework grounded in safety science and production systems research. A systematic literature review was conducted following the SALSA protocol, covering peer？reviewed journal articles published between 2020 and 2025 in Scopus, Web of Science, and Google Scholar. After applying rigorous inclusion and exclusion criteria, 17 studies were retained and analyzed using thematic analysis. The synthesis indicates that legal compliance and formal OHS management systems alone are insufficient to explain variations in safety performance in internally outsourced environments. Instead, OHS outcomes emerge from interactions among governance arrangements, contractual mechanisms, human resource practices, procurement logics, and digital technologies. Building on these findings, the paper proposes an integrative sociotechnical framework that explains how safety performance is shaped by interorganizational coordination, power asymmetries, and decision？making structures in fragmented production systems. The study contributes to safety science by advancing a mechanism-based explanation of how OHS performance emerges in fragmented, multi-employer production systems and by articulating directional propositions for future empirical testing.