Research On Product Quality Risk Assessment Of Manufacturing Industry Based On Life Cycle

China is a manufacturing power. Its rapid social development witnesses a growing proportion of manufacturing in GDP as a whole. However, accidents caused by quality risk always occur, bringing harm to enterprises as well as personal security and property safety. In order to put them under control and lower harm influence, we must conduct quality risk assessment, which has been increasingly noticed by our society.In recent years, applied risk management methodology has been put forward as a new approach to improve quality risk management. Considering long and complex quality product manufacturing process and numerous risk sources influencing product quality, many scholars do their research based on manufacturing supply chain or on a certain production life cycle. However, this paper uses cloud model to assess quality risk on a basis of the overall manufacturing life cycle.Under the introduction part, the history of both domestic and foreign quality and risk management theories is mentioned. Meanwhile, this paper summarizes five periods of manufacturing life cycle----market research, product design and analysis, product procurement, product manufacturing and product delivery. Then, historical document analysis, brainstorming method, workflow analysis and fishbone diagram method are used to identify and list 21 quality risk factors. During the classification and sifting process, expert advice are considered, and minor or irrelevant risk factors are ruled out.Considering China’s fledging quality risk assessment methodology, much uncertainty in quality risk assessment, low document record and immature assessment theories, quality risk levels cannot be rated through existing records. So expert experience are put into thought. This paper creates quality risk probability table, quality risk principle table and risk rating table. Upon that, expert are invited to evaluate quality risk probability. But individual expert evaluation makes hard to ensure tests’accuracy and objectivity. Furthermore, existing interval research is based on bin endpoints. The value of bin endpoints are full of uncertainty and easy to be ignored. Therefore, this paper use cloud model to fuzz and randomize experts’ evaluation results so as to objectively acquire the value of each risk factor as well as the overall risk value under each period of the life cycle.In this paper, the method of weighted average operators is adopted. Cloud model risk factor matrix is multiplied by cloud weight matrix of each risk factor to acquire risk values and rates of each period under the life cycle. Then risk values of each period under the life cycle based on the cloud model are multiplied respectively by cloud weight matrix of each period to acquire the overall product risk value and rate. Finally, the above method is used on Y company to assess the quality risk of its tin.In this paper, membership function based on the cloud model risk evaluation takes into consideration the uncertainty and fuzziness of risk evaluation and realize the conversion between qualitative and quantitative evaluation. What’s more, it shows the volatility and uncertainty of risk evaluation results, thus injecting new thoughts on risk evaluation analysis.