Lean 4.0 Integration for Sustainable Industrial Performance: A Strategic Framework for Combining Lean Management and Industry 4.0 Technologies

Manufacturers are under simultaneous pressure to raise productivity, respond faster to volatile demand, improve resilience and reduce the environmental and social burdens of industrial activity. Lean management and Industry 4.0 are frequently presented as complementary responses, yet the literature still contains fragmented guidance on how their integration should be sequenced, governed and measured. This review synthesises recent evidence on Lean 4.0 and develops a strategic framework that connects lean operating discipline with digital sensing, connectivity, analytics, automation and closed-loop learning. A structured integrative review of peer-reviewed research published from 2020 to 2025 was undertaken, with emphasis on studies that examined explicit interactions between lean practices and Industry 4.0 technologies, implementation conditions, organisational capabilities and sustainability outcomes. The synthesis shows that digital technologies generate stronger benefits when they amplify a stable lean system rather than automate poorly designed processes. Lean provides problem visibility, process ownership, standardisation and customer-value logic; Industry 4.0 extends these capabilities through real-time transparency, predictive intelligence, traceability and adaptive control. The proposed framework therefore organises Lean 4.0 as a five-layer system comprising lean stability, digital visibility, analytical intelligence, responsive execution and sustainability governance. It also specifies a staged implementation pathway and performance architecture spanning operational, environmental, economic and social indicators. The review identifies workforce capability, data governance, interoperability, leadership commitment and disciplined technology selection as critical boundary conditions. The resulting framework positions Lean 4.0 not as a technology programme but as a strategic operating system for sustainable industrial performance.