Defect Reduction in Gear Production : A Case Study of Motor Component Manufacturing

Abstract

This research aimed to reduce the defects of a gear production by using DMAIC principle stage of Six Sigma technique. According to the case study company’s target, the main problem was the over specification of 50%  .The research methodology consisted of 5 steps : (1) Defined phase, the pareto diagram was use to define the problem (2) Measure phase,  the root cause of problems wear determined, (3) Analysis phase, (4) Improved phase, the design of experiments (DOE) with 2² Factorial Design, Operation standard and Gauge Repeatability and Reproducibility (GR&R) (5) Control Phase, the Work Instruction (WI) is applied to control the process. After improvement by implementing the DMAIC method, it found that the scrap rate was reduced from 3.40% to 0.91% of all defect rates. Thus,as this improvement the amount of defects can be reduced by 76.47% more than of company policy.