Application of FMEA to reduce wastes in the plastic injection molding industry : case study of AB Company

Abstract

This research aimed to 1) study problems occurring from the plastic injection molding process, 2) analyze and investigate the root causes of the problem and reduce waste from the plastic injection molding process, and 3) reduce production costs from the plastic injection molding process and increase productivity by reducing waste. The results showed that conducting root cause analysis using a Pareto diagram and a cause-and-effect diagram indicated that the defects were caused by black or colored spots on products in the production process. Moreover, conducting problem analysis by using the FMEA technique indicated that before the process improvement, the average RPN was 155.75 points and after the process improvement, the average RPN was 17.50 points, decreasing to 138.25 points. In addition, the main problem in the production process was insufficient cleaning of machinery and equipment. In addition, operators still did not understand the steps for cleaning and maintaining machinery and equipment which caused small powder, dust, and scraps. These could cause black or colored spots on the products in the production process. After the process improvement, the waste was reduced by 99.455 percent and the cost was reduced by 776,540 baht.