Tri-dimensional review on integrating industry 4.0 and Lean Six Sigma for manufacturing excellence

Integrating Industry 4.0 (I4.0) technologies with Lean Six Sigma (LSS) tools holds significant potential for enhancing manufacturing excellence (ME). This paper provides a comprehensive review of 181 research articles published from 2016 to September 2025 on I4.0 technologies, LSS tools, potential synergies from their integration, and critical success factors (CSFs) for the successful integration of these two notions. A systematic literature review (SLR) that consists of descriptive, bibliometric, and detailed content analysis. This tri-dimensional analysis was performed using data retrieved from the Scopus database and analysed through the Bibliometrix package of Biblioshiny interface in R Studio (version 4.4.1), and VOS viewer. The study aims to identify key LSS tools and I4.0 technologies, CSFs, and their synergies, to ultimately support manufacturing firms in surmounting current challenges, recognizing and capitalizing on emerging opportunities, and eventually cultivating a culture of continuous improvement. The findings revealed that integrating these two paradigms can streamline operations, enhance quality, and optimize manufacturing operations. However, this integration necessitates careful consideration of CSFs including management support, resource allocation, comprehensive training, and a few more. In the end, this research contributes to the progression of the research field by pinpointing future research avenues. The novelty of this research lies in its unique phased roadmap, which outlines all necessary LSS tools, I4.0 technologies for each phase, with consideration of CSFs.