Sustainable Lean Six Sigma Framework for Waste Management in Healthcare 4.0

Healthcare waste management (HWM) remains a challenge in developing countries, where deficiencies in waste segregation, treatment, disposal, and resources undermine environmental and operational performance. This research develops and validates a Sustainable Lean Six Sigma (SLSS) framework for healthcare waste management in Healthcare 4.0 environments by integrating the DMAIC method (Define, Measure, Analyze, Improve, and Control) with sustainability metrics and Industry 4.0 technologies. A mixed-method design was adopted comprising three phases: a PRISMA-based systematic literature review; a three-round modified Delphi consultation with 25 experts; and a 12-month pre–post quasi-experimental implementation across tiered healthcare facilities in Pakistan. The framework resulted an improved waste segregation accuracy by 32 percent, an increase from 62% to 94%, while infectious waste decreased by a raw 38% (108.5 to 67.3 kg/day) and by 18.8% after reclassification correction (73.8 to 59.9 kg/day), with the difference reflecting the improved classification of previously over-classified waste through IoT-enabled real-time monitoring. Waste-handling costs declined by 30%, carbon footprint decreased by 41%, and staff compliance with waste-management protocols increased from 58% to 91%. The intervention achieved an 87% return on investment, with a benefit–cost ratio of 1.87:1. The research contributes a replicable SLSS model for resource-constrained healthcare systems, as characterized by sequencing of characterization, monitoring, training, and infrastructure; gamified training with real-time IoT feedback; and resilience measures for unreliable electricity, including UPS backup and offline data collection. This research provides an empirical validation of an integrated SLSS–Industry 4.0 sustainability framework for Pakistan.