Six Sigma for process improvement in manufacturing: A case study

Abstract

Six Sigma is one of the most powerful management tools used to achieve process excellence. Six Sigma was developed as a method of quality improvement through the elimination of operational defects. Therefore, the objective of this study is to review the Six Sigma theory and apply it to the case study of company A, which specializes in the production of helmets in Vietnam, to reduce the styrofoam defect rate of helmets. The DMAIC (Define - Measure - Analyze - Improve - Control) process of Six Sigma is applied in this improvement project. The results show that the styrofoam with the main defect is the Structure. From there, the root causes are analysed, and solutions are suggested. After the improvement, the Structure defect rate decreased from 1.15% to 0.38%; the Sigma level increased from 3.77 and 4.17, cost of quality was significantly reduced. The success factors of the project are leadership, employee involvement, project management, and data collection. A barrier to the project is communication channels between levels of the company.