Uncertain random fault tree analysis based on cloud security protection framework
Changyou Guo1, 2, 3, Xuefeng Zheng1, 2, Jianjun Liu3
1School of Computer and Communication Engineering, University of Science and Technology Beijing, Beijing, China
2Beijing Key Laboratory of Knowledge Engineering for Materials Science, Beijing, China
3Department of Computer Science, Dezhou University, Dezhou, China
Based on uncertainty theory and chance theory, this paper proposes a method that constructs and analyses fault tree. The fault tree is constructed based on logical relations between bottom events. Fault rate of bottom event would be characterized as random variable if it is obtained from historical data, it would be characterized as uncertain variable if it has no statistical data but is obtained from expert's subjective judgment. The chance that top event occurs is an uncertain random variable. The minimal cut set of fault tree is obtained by Boolean algebra method and at same time, the simplest standard disjunction expression of top event is obtained. This paper also constructs hybrid simulation algorithm to calculate the chance that top event occurs. At last validity of this method is confirmed by taking cloud security protection framework risk fault tree as example.