The ready-made garment (RMG) industry in Bangladesh, with the gradual increase of manufacturing costs, is in indispensable requirement to initiate improvement in manufacturing to continue sustainable growth for long run. With the customer expectation, it is required for the manufacturer to improve capacity, on-time delivery, efficiency, and financial condition. To achieve that, it is required to optimize cycle time to improve capacity, reduce work-in-process (WIP) and throughput time to get faster flow and delivery, optimize process and resources fulfilling the expected quality. This study aims to improve manufacturing performance using a layout optimization methodology and workplace engineering through the work study. The proposed methodology is implemented in a RMG finishing production line. The results show that, about 19.5 sec cycle time is reduced by increasing 16 pcs capacity per hour from the line. Also, 2 manpower is optimized from 8 lines through process elimination which impacts 3% efficiency improvement, whereas throughput time is reduced to 26 min by cycle time minimization and WIP reduction to improve on-time delivery. These are the two most effective tools for improving the workplace, work environment as well as manufacturing performance. The proposed layout optimization and workplace engineering can be implemented in any type of industry to improve lead time, quality, material handling as well as customer satisfaction.