<p>Inefficient facility layouts continue to be a significant source of waste in garment enterprises, resulting in excessive transportation, work-in-process accumulation, ergonomic strain, and unstable production flow. Although Lean production offers practical tools to mitigate these issues, layout redesign decisions in practice are often made intuitively, lacking structured analytical decision support. This study proposes a Lean-oriented facility layout optimization framework that exclusively employs Multi-Criteria Decision-Making (MCDM) to support layout selection. The framework integrates workplace and process stabilization through 5S and standardized work with a hybrid AHP-COPRAS (Analytic Hierarchy Process-Complex Proportional Assessment) model to evaluate feasible layout alternatives. Four main criteria and thirteen sub-criteria reflecting flow efficiency, cost efficiency, human factors and safety, and scalability were developed based on Lean principles and field observations. Three layout configurations-straight-line, parallel-line, and zigzag were evaluated in a real garment in Vietnam. The results indicate that the parallel-line layout achieves the highest overall performance by effectively balancing flow continuity, ergonomic conditions, and implementation cost. Following implementation, the selected layout resulted in a 23% reduction in transportation distance, a 49% increase in productivity, and a 52.8% decrease in defect rate. The findings demonstrate that embedding MCDM into a single, foundational Lean decision, namely, facility layout redesign, provides a practical, analytically robust, and replicable pathway for improving operational performance in resource-constrained garment.</p>