Abstract: Study is conducted for the improvement of an existing electric power-driven tool production line.By using the data collected from the production process,the value-stream state chart is drawn.With this chart,the layout and line balance analysis is carried out.In this way,the bottleneck that affects the key performance indicators (KPIs),such as productivity and equipment utilization,is identified.With lean production principle,the production lines are redesigned such that the bottleneck is eliminated and the performance is improved.