Improving the yarn production process by design for Six Sigma approach

At present, a large part of production costs and quality problems are related to design. Design for six sigma is a powerful approach for the design and development of products and services. The purpose of this research is to use design for six sigma to reduce the defects of spinning yarn. For this purpose, after examining the production line of spinning yarn, using Pareto diagram, the most important yarn defects were identified, which are: thick and thin. Then, the initial model was simulated and validated in Arena 14 software and the level of the existing process sigma was determined. In the next step, the optimization model was examined by this software. The research results show that the validated model can determine the optimal values well and significantly reduce the costs of performing multiple tests to reduce the amount of yarn defects. The results also showed a 1.55 unit improvement in the process sigma level.