Bridging Continuous Improvement and Smart Manufacturing: A Comprehensive Review of LSS and Industry 4.0 Integration

With Industry 4.0, modern manufacturing systems have undergone significant changes, allowing the collection of data in real time, automation through intelligent systems, and interconnection of production environments. At the same time, one of the most popular approaches to continuous improvement is LSS (LSS), which focuses on the eradication of waste, the efficiency of the process, and the enhancement of quality. The combination of LSS and Industry 4.0 is a developing area of research, even though combining these two paradigms is complementary. This article includes a systematic literature review in which the combination of LSS practices and Industry 4.0 technologies, including the Internet of Things (IoT), artificial intelligence (AI), cyber-physical systems (CPS), and big-data analytics, is discussed. The literature review is based on recent publications published between 2018-2025 and relies on significant academic databases such as Scopus and the Web of Science. The results show that Industry 4.0 technologies significantly improve traditional LSS instruments such as value stream mapping, root cause analysis, and statistical process control owing to their ability to monitor reality in real time, predictive maintenance, and decision-making based on statistics. Nevertheless, integration has also brought up several challenges, including the resistance of the organization to digital transformation, the high cost of its implementation, the skill gap among employees, and cybersecurity issues. Through an overall summary of the available literature and industry case studies and analyses, this study suggests a template for integrating LSS approaches into Industry 4.0. The proposed framework provides viable recommendations for organizations planning to shift to intelligent, data-driven, and sustainable manufacturing systems.