The purpose of this paper is to propose a comprehensive methodology for reducing mold changeover time in the plastic injection molding industry by using Lean Manufacturing tools, the approach, and SMED techniques enhanced with artificial intelligence (AI) for decision- making and optimization. First, we will identify the problem using the 5-Why tool. The measurement phase involves the collection of data using time studies and computer-aided design (CAD) to identify failures. In the analysis phase, we will try to address critical tasks and support our analysis with Failure Mode and Effect Analysis (FMEA). The innovate phase enables us to improve the sequence of external and internal tasks, using real-time data to adjust the process. In addition, the methodology helped to balance the production line by redistributing tasks and reducing bottle- necks, hence improving flow and reducing downtime. Application of this approach not only reduced mold changeover time by 65%, but also improved the overall balance of the production line, therefore boosting productivity and operational efficiency. The control phase led to standardize these improvements, re-establish a continuous process improvement cycle, and establish a sustainable line balance. Furthermore, continuous improvement is ensured through standardized control mechanisms powered by fuzzy decision systems, thus establishing sustainable and optimized line balancing.