Research On The Application Of Safety Critical Degree Of Product Components

With the development of science and technology, products have become more and morewidely applied in our daily life. Many kinds of products have been used in different fields.Even the purposes of products are different, the function and safety are the basic conditionsfor products’ development. In order to ensure the users, environment and property can protectthemselves from being affected by any mishap, and find out scheme to make the safety ofproducts is optimal by product design.For solving the problem of product design, such as time, cost, effectiveness of productsafety design, in order to find the components which have the most influence on productsafety, this is safety-critical items. This paper is based on the calculation of safety-critical ofmachinery＆electrical products, and use the safety-critical degree to make the composesarrange from critical to general. With the characteristics of the product itself and the indexesof product which is influenced by the items, the failure models which lead to it’s failing andthe factors should be considered. Firstly, according to the risk severity categories, evaluate theconsequences of the components, and make sure the method to adjust the sort of componentswith the risk severity categories. Secondly，defined the component which is probabilitysensitive item and probability changes sensitive item, and analyzed the components whichtake part in many different failure models under different conditions. Then calculate theprobability of every component of the importance and key importance. Solved thecomponents which involved in single or multiple consequences of different fault tree. How touse the critical degree to adjust the deviation of theory and practical. Thirdly, according to theobjective condition, such as processing technology, using environmental and so on. Weestablished the comprehensive ranking criterion. We will be better know the sort of criticalcomponents, according to the application during the product design. Finally, car’s brakesystem was cited to validate the model, based on safety-critical values to sort safety criticalcomponents, and put forward the improvement method of adjustment and design.