DEFECT REDUCTION IN TRIMMING AND FINAL ASSEMBLY LINE OF A TRUCK PRODUCTION WITH DMAIC METHOD

Abstract

Quality is an essential thing in the automotive industry, especially for an established truck manufacturer. PT. HMMI had found 1,788 defects in 34,381 productions in the last year before the Covid-19 spread made the orders for trucks decreased enormously. This research aimed to find out the major defects among the all of defects occurred, recognize what caused the defects, and determine what actions can be done to prevent the defect in the light duty truck assembly line with the DMAIC method. The analysis used statistical process control tools such as the Pareto chart, Fishbone diagram, and control chart, and failure mode effect analysis to find the root cause and determine the action to prevent the defect later. The analysis found the major defects are door scratch, wheelhouse scratch, and cabin contact. The action planned to reduce or prevent the potential cause are more supervision to the working workers, apply protector to the wheel house, add fasten the left and right bolt simultaneously on the work instruction, and install stopper beside the cabin hook. The research result reduced the defect rate for 21.96% and reduced the major defects proportion.