Auto parts manufacturing quality assessment using design for six sigma (DFSS), case study in ISACO company

Abstract

During recent years, six sigma has been used as effective tool in quality management system in various industries in order to reduce wastes. Design for six sigma (DFSS) is one of the six sigma methodologies. It is a complex and powerful mechanism that can help us to increase success for new technology or product. In this research, we develop a framework to evaluate the quality of EF7oil filter, using Identify—Characterize—Optimize—Validate (ICOV) approach; one of the DFSS methods. In first phase, we should ensure that none of the customer needs have not ignored. For this purpose, we identified all customer needs and then prioritized them using analytical network process method, after that, we prepared a list of technical requirements to meet mentioned needs. At the second phase, we prioritized failure causes of a filter using six sigma tools such as cause and effect diagram, Failure mode and effect and House of quality. Then choose the most important failure causes for action improve practices to achieve the appropriate sigma level. We understood that the most important needs of costumer is “no tear or hole in filter paper” and also the lack of structure in this filter is the main factor of oil filter failure which causes to decrease the sigma level to 4.83. Finally by prioritizing the technical requirements, determined that the designing an interior structure with the importance of 3.02 is the most important of design requirement that doing necessary changes can improve significantly the sigma level. Gathering all of these phases in one structured framework, “ICOV”, leads to develop the appropriate infrastructure which is used by various industries including automotive industry. It reduces the confusion in using the large number of quality techniques and tools in order to take effective preventive and corrective actions in production processes, instead of just doing final inspection and achieving customer satisfaction.