Lean concept to reduce waste of process time in the plastic injection industry in Indonesia

Abstract

The mapping that has been done previously shows that there is a high processing time for the injection molding and shaft assembly processes in the S/A worm gear-type plastic industry. The purpose of this research is to identify and reduce waste in the injection molding process and the shaft assembly process to increase the amount of production. The research uses the lean concept approach method with the identification of causes carried out using the What-Why-Where-When-Who-How (5W+1H) method in focus group discussions (FGD) with competent parties in their fields. This study found that the type of waste obtained from the length of processing time (PT) from the injection molding section was 83.69% or 120.18 seconds and the shaft assembling section was 15.58% or 49.13 seconds, in total the processing time before improvement was 194.87 seconds. This research resulted in the injection molding processing time being reduced by 32.70% and the shaft assembly process by 37.82% with the change in processing time reduced by 26.40% so production results increased by an average of 103% per month.