Improving the assembly line with lean techniques: An application in medical devices industry

To gain a competitive advantage in the market that the customers determine the product price wherein the high business competition environment, businesses try to find innovative and flexible manufacturing methods to fulfill customer demands. One of the methods they can achieve business goals is the lean production method. By employing this method, wastes that do not add value to the final products and processes are detected and minimized. Then the consistency of customer satisfaction and business objectives can be maximized. In this study, the assembly line of a product family selected as a pilot in a company that produces medical gas systems products in the medical device industry has been examined. Value definition has been made for the selected product and current and future state value stream maps have been prepared. Work steps in the assembly line were determined, wastes in the processes were identified and improvements were made. Standard times of all activities were calculated by time study. In addition, the standard times of activities on a selected assembly line were calculated using the Methods-Time Measurement (MTM-1) method (a type of Predetermined Time Standards (PTS)) and compared with the time study results. Instead of the existing assembly line, it has been proposed to establish a u-shaped assembly line in accordance with the lean production philosophy where the company can use its workforce flexibly according to the order size from the customer. 3 different alternative assembly lines were designed. Compared to the current situation, it has been calculated that the balance delay of the assembly line can be improved by 70%, the daily production amount per operator can be improved by more than 90% and the required working area for the assembly line can be reduced by 40%.