This report investigates the application of lean principles in preventative maintenance within the after-sale services industry, focusing on a GCC Engineering, Procurement, Construction company. The study addresses backlogs, delays, and various wastes in the maintenance facility, outlining objectives for lean processes. Methodology involves meetings, Gemba Walks, interviews, data collection, gap analysis, Kaizen improvements, and standardization. Numerical and contextual data reveal worker movements, waiting times, overprocessing, and a lack of standardization. Proposed improvements, such as tool belts, movable storage units, ERP systems, and Kanban boards, aim to mitigate these issues. Graphical representations illustrate the future state spaghetti diagram, standardized work, and 5S implementation. Results indicate substantial improvements, including an 84.31% to 92.16% decrease in lead time, an 83.33% to 340% increase in capacity, a 65% decrease in the number of steps, and a 66.67% to 75% decrease in inventory replenishment cycles. The conclusion emphasizes the achievement of all objectives and the unique contributions of the research, offering practical solutions aligned with industry needs. The organization anticipates positive shifts in operational dynamics and long-term success as these recommendations are implemented