中文摘要：

在研究系统安全性的实际过程中发现,影响系统的因素很多情况下表现出来的是一个区间域值。特别是对复杂系统影响因素的提取,往往是靠长时间使用者的经验给出的导致系统失效的因素范围值。就该问题提出了系统T在属性a为区间域值的情况下对对象集U的划分决策规则。从基础信息决策表出发,计算相似度S（xi,xj）得到相似度矩阵,在定f情况下划分每个对象聚类C（xi）,并进行聚类化简得到U={L（X1）,…,L（XR）},根据决策集D的聚类划分得到U划分类到决策D之间的类对应规则,最后得到决策模式D（di）。列举了一个电器系统例子,针对其环境变量（使用时间和使用温度）在不同范围组合下对系统安全性等级的影响进行了划分,并得到了决策模式及分类。

英文摘要：

In the actual process of study on system security,it has been found that the influence factors of the system show as the interval domain value in many cases,especially when extracting the influencing factors of complex systems,it usually depends on the range value of the factors leading to the system failure,given by the experience of users in a long time period.In order to solve the above problems,the classification decision rules of the object set U was put forward considering the interval domain value of attribute a in the system T.Based on basic information decision table,the similarities S（xi,xj） were calculated to composite the similarity matrix.Under the condition of given f,each object cluster C（xi） was divided and simplified to U = { L（X1）,…,L（XR） }.According to the cluster division of decision set D,the corresponding rules from U to D were obtained.Finally the decision model D（di） was build.For an example of electrical system,the influence of system security level in view of its environment variables（using time and temperature） under different scope combinations was classified,and the decision model and classification were obtained.