The growing emphasis on environmental sustainability has drawn considerable attention from both academia and industry practitioners. Factors such as escalating energy costs, heightened environmental degradation, and a burgeoning market demand for eco-friendly practices have compelled businesses to reassess their strategies through a green lens. Given that Lean principles are rooted in optimising operations to minimise waste across design and production processes, their synergy with the green paradigm is evident. However, despite the intuitive connection between Lean methodologies and environmental sustainability, the scholarly exploration of their impact remains largely underdeveloped. This research seeks to bridge this gap by conducting a comprehensive systematic literature review to dissect the current understanding of Lean manufacturing practices and their influence on environmental sustainability performance. The selected papers were meticulously screened and grouped into three clusters using the PRISMA diagram methodology. The primary objective was to discern the tangible effects of Lean practices on eco-efficiency performance and explore integrating Lean manufacturing principles with broader sustainable manufacturing approaches. A structured matrix was created to categorise and visualise the identified impacts gleaned from the initial articles. Nevertheless, the review revealed significant gaps in understanding, particularly regarding the factors that shape the efficacy of Lean manufacturing tools in enhancing eco-efficiency performance. The findings underscore the need for further research to unravel these complexities and delineate the mechanisms through which Lean practices contribute to environmental sustainability. Several avenues for future research have been delineated, focusing on how Lean manufacturing practices can be leveraged to support eco-efficiency performance effectively. While the preliminary findings shed light on the promising intersection between Lean principles and environmental sustainability, they also underscore the imperative for continued scholarly inquiry to unlock the full potential of Lean methodologies in fostering a greener industrial landscape.

Lean is a management paradigm that focuses on respect for people and promises improvement in a company’s performance across sectors and sizes. SMEs, in particular, are a point of interest, considering that their malleability in bureaucracy allows for a more significant margin of continuous improvement application. Several organizational theories have gained advantages from technological innovation, and Lean is no exception. The relationships between Lean and new technologies have been studied throughout the years and gained particular interest in the years when Lean started to be integrated with Industry 4.0 (I4.0) to enhance firms’ performance. This article would like to take that discussion from a different point of view, that of I4.0's impact on proving the importance of implementing Lean in manufacturing companies. Through a mixed-method approach of case study and Simulation, this article will answer the identified research question: "How do Lean tools and their integration impact SMEs’ process performance?" by showing the importance of implementing Lean tools in a non-Lean company. The results show that Simulation can identify the Lean tools that benefit the company’s performance most. Managers could benefit from this study by highlighting which tool or combination to invest in according to the impact on operational performance.

Lean manufacturing can be considered a socio-technical system integrating both technical tools and human-centered, or soft, practices. While extensive research has examined technical aspects, the contribution of soft Lean practices focused on human behavior to environmental sustainability remains underexplored. This study addresses this gap by examining how soft Lean practices can help overcome barriers to environmental performance in large-scale production systems (LSPSs), using Italy’s food manufacturing sector as a case study. A multi-case study methodology was employed, involving five companies. Data were collected through interviews conducted across top management, middle management, and operational staff levels to capture diverse perspectives. Using variables extracted from the literature and a deductive coding approach, the study identifies (1) the specific soft Lean practices adopted and the perceived environmental performance barriers at each hierarchical level, (2) differences in interpretation of these practices and barriers across hierarchical levels, and (3) how soft practices can mitigate obstacles to sustainable performance. The results demonstrate that soft Lean practices, when aligned with organizational structure and culture, can effectively mitigate barriers to environmental improvement. This research contributes to the Lean and sustainability literature by offering a multi-level perspective and practical insights into integrating human-centered approaches within industrial sustainability strategies.