This article aims to explore lean manufacturing principles within the context of Industry 4.0, focusing on how Lean practices drive adoption and enhance operational performance through digitalization and advanced manufacturing technologies in a rebar manufacturing company from Bosnia. Practical insights illustrate the application of Lean 4.0 principles in reducing non-value-added activities in the process by demonstrating tangible benefits in terms of operational efficiency. Specifically, process cycle efficiency for the sample carrying from Mesh factory to the Quality Control department was analyzed. Results showed that the efficiency of the current process was 9.89%, which is in alignment with the literature. By integrating Lean 4.0 strategies, which combine traditional lean methods with advanced digital technologies, significant improvements were achieved by the elimination of some non-value-added activities. As a result, the efficiency of the optimized system was increased to 13.91%, demonstrating the practical benefits of Lean 4.0 in streamlining industrial processes. This case study highlights how adopting lean methodologies can effectively optimize operations, reduce waste, and boost competitiveness in the evolving landscape of Industry 4.0.