Reduce cycle time and work in process in a medical device factory : scheduling of needle hub molding machines

Abstract

Many manufacturing firms have improved their operations by implementing a work-in-process (WIP) limiting control strategy. This project explores the application of this concept to limit WIP and reduce cycle time for the Becton, Dickinson and Company's manufacturing facility in Tuas, Singapore. BD's Eclipse Safety Needle production line is facing increasing pressure to reduce its high WIP and long cycle times. With the forecast of increasing demand, the current production control practice will sooner or later push the shop floor space to a limit. We divided the overall system into three manageable sub-systems and analyzed different strategies for each. This paper documents the approaches to schedule 30 molding machines. These machines are located at the first stage of the production line. Although the total production rate of the 30 machines is higher than the downstream machines, the production rate of each product type is much slower because of machine constraints. This project groups the 30 machines into three groups, and proposes different strategies to reduce the total WIP level and cycle time.