Case Study On Design Of Experiment For Cold-rollers And Electronics Products

With the social progress and the increasingly rich material, it is getting higher and higher quality requirements for products or services by people, and so quality management has been receiving increasing attention. However, because of their poor-quality and low-grade products, the majority of enterprises in China are at a disadvantage in the face of fierce competition in the global market. This situation is directly due to poor technological innovation and low level of quality improvement. Design of experiment is a kind of tool in technological innovation and quality improvement and has a wide range of application. Therefore, it is an important strategic move to promote design of experiment in the enterprises,as it can change the aspects of backwardness to some extent in China's technological innovation and quality improvement.This thesis is a part of the preliminary technical cooperative project "Cold-rollers Quality improvement and Evaluation System"and business management consulting co-operation project "DaFeng electronics quality management consulting project".According to the different characteristics of products in different sectors, this thesis applies two different methods of design of experiment-factorial design and response surface methodology design to the steel and electronics industries.Through the implementation of factorial design in cold-roller plant of the BY company and the implementation of response surface method design in DaFeng Electronics Co., Ltd, the related technology in the production process of the two companies has been improved and the process parameters have been optimized.Therefore, design of experiment has been applied to the two companies successfully and the quality of their products obtaines much improvement.Firstly, this thesis summarizes the basic theory and different methods of design of experiment, and how to apply the statistical analysis software Minitab to design of experiment in detail. Then, this thesis focus on the prominent issues of the quality which exist in cold-roller products of BY companies and proposes a plan of design of experiment in heat treatment process combined with characteristics of cold-rolerl products. Through the implementation of this plan in production process, the plan achieves good results. Then again, in view of the issues about high rate of spot welding non-performing that exist in micro-controller products of DaFeng Electronics Co., Ltd, this thesis proposes a plan of design of experiment in the process of spot welding process about the production of the micro-controller and applies this plan to the production process,combined with the characteristics of electronic products. This thesis applies two different kinds of design of experiment to the production process of cold-roller and micro-controller products and has achieved Success. Design of experiment not only has played a positive role in promoting the quality of products in the two companies, but also has played a good role in applying design of experiment to the other enterprises of steel and electronics industry.