Editorial note

We take immense pleasure in bringing to our readers a special issue on Leans Six Sigma (LSS) and Industry 4.0 (I4.0). The advances in I4.0 have transformed modern organizations into digital ecosystems. The traditional functions of organizations have undergone significant changes due to digital transformation, radically changing the manner they design, manufacture, sell, distribute and maintain their products and services. Modern technologies such as Internet-of-Things, cloud computing, cyberphysical systems, big data analytics, among others, are used distinctly, in all the phases of the product life cycle. Present-day manufacturers are integrating new technologies into their production facilities and throughout their operations to achieve the new level in operational excellence and superior performance in quality and reliability. However, for achieving sustainable competitive advantage using modern technologies, operational excellence methodologies, such as LSS, have to be effectively integrated with I4.0 technologies. Antony et al. (2021) put forward a sand cone model to demonstrate the cumulative evolution of LSS methodology from LSS1.0 to LSS4.0. However, the integration of LSS and I4.0 has not been empirically investigated so there is uncertainty about how I4.0 and LSS support each other. The main objective of this special issue is further the research in this area. The following article is included in this edition: The first article “A systematic review of the integration of Industry 4.0 with quality-related operational excellence methodologies” is contributed to the special issue by Komkowski, T., Antony, J., Garza-Reyes, J.A., Guilherme, T. and Tanawadee, P.E. The authors through a systematic literature review (SLR) examine the common themes for integrating Industry 4.0 with qualityrelated Operational Excellence methodologies. They further provide a comprehensive overview of ‘what’ and ‘how’ to combine them in an initial integration process. This research presents a holistic view of Quality Management (QM) and I4.0 integrations. They critically analyze the literature from 2015 to 2021 and suggest future research opportunities in the area of I4.0 and various quality improvement methodologies such as Total Quality Management, LSS, and Business Process Management. Additionally, they study resources, capabilities, and other characteristics required for QM and I4.0 integrations. This study could be a starting point for future investigations. The second article “Industry 4.0 and Lean Six Sigma integration in manufacturing: A literature review, an integrated framework and proposed research perspectives” is contributed by Skalli, D., Abdelkabir, C., Cheraffi, A., Graza-Reyes, J.A., Antony, J. and Shokri, A. This is also a literature review; however, it explores the literature on lean management (LM), Six Sigma (SS), and I4.0 and its relationship. This study uses an SLR methodology along with bibliometric analysis to analyze 134 articles between 2011 and June 2022. They further identify the impact of I4.0 technologies on LM, SS and I4.0, the relationship, and the implications of their combination on operational excellence. One of the main findings of the study is that researchers consider I4.0 to be a driver of LSS. They also provide an overview of the main research streams in this field, and their shortcomings and present an LSS4.0 framework integrating lean six sigma and I4.0. The third article is looking into “Lean and Industry 4.0: A bibliometric analysis, opportunities for future research directions” by Alsadi, J., Antony, J., Mehzer, T., Jayaraman, R. and Maalouf, M. The authors through a bibliometric review analyze Lean I4.0 or Lean 4.0 and Lean digital transformation literature for identifying its state of art, benefits, challenges, and scientific gaps. The analysis is carried out from 2010 to 2022 from the Scopus database. The study concludes that Lean I4.0 and Lean digital transformation tend to be a field of active and extensive research in the last five years. The rate of growth of publications follows exponential growth. The paper further contributed by highlighting the benefits and challenges while integrating Lean and I4.0 or Lean and digital transformation, besides focusing on the future research gap. The last paper of this special issue presents “Lean Industry 4.0: Past, present, and future” from a leading Lean academic and practitioner Hines, P.A., Guilherme, T., Antony, J. and Romero, D. This paper uses a real-time, open-question qualitative survey method for exploring the past, present, and future of Lean I4.0. The study finds that the background of researchers in this area is from Europe and Asia, with an academic background in engineering. The main research interest in this area is on I4.0 technologies, sustainability, I4.0, supply chain and people. The research also suggests that there is no agreeable definition