Improving manpower utilization through work-study and lean techniques: A case of manual assembly

Despite technological advances, many manufacturing industries continue to rely on manual assembly lines. However, manual assembly lines often experience situations of underutilized manpower due to inefficient workload distribution and suboptimal work methods. The ability to optimize manpower utilization in labour-intensive operations remains a decisive factor in sustaining operational efficiency while contributing to better workforce morale and engagement. This paper presents a case report of optimizing manpower utilization in a manual assembly process in Sri Lanka. The main objectives of the study were to investigate the current state of manpower utilization in the manual assembly process and optimize the manpower utilization using work study and lean techniques. These objectives well align with Sustainable Development Goals (SDGs) of Decent Work and Economic Growth (SDG 8), Industry, Innovation and Infrastructure (SDG 9), and Responsible Consumption and Production (SDG 12). Through systematic analysis of work methods and time measurement data, this study developed an evidence-based framework for manpower optimization. The findings provide an essential understanding of the interconnected impact of work method inefficiencies and workload imbalances on manpower utilization. This led to the optimization of manpower utilization through improved work methods and workload re-distribution without altering the plant's existing level of automation to create more efficient and sustainable production processes with increased worker well-being. Overall, the holistic methodology adopted in the study can be replicated to optimize manpower utilization in numerous contexts across different types and sizes of organizations.