IMPLEMENTING SIX SIGMA METHODOLOGY TO IMPROVE THE QUALITY OF WELDING IN PT. X (A CASE STUDY ON AN MINING INDUSTRY)

Abstract

This paper focuses on a quality improvement project at PT. X by using Six Sigma methodology. The study is aimed at providing improvement ideas for existing problems in the welding process for product Lower Mast RIG PD 350HP Carrier Rig. Investigations were conducted to identify causes of defects. Using result of unstructured interviews, and relevant data from factory observation, the problem was analyzed using cause and effect diagram where the main causes were identified. To improve the existing problems, alternative is evaluated in term of its expected potential improvement and estimated cost of implementation. The evaluation indicates that Six Sigma methodology proved to be the best alternative. This alternative was later presented to the company’s management for further evaluation and comments. The study culminates with proposed solutions to improve productivity at the factory and future study.