Belief reliability analysis of competing for failure systems with bi-uncertain variables

In this paper, an uncertain competing failure degradation model is proposed, in which the natural degradation process is described by an uncertain process, the time interval of shocks arrival and the size of the shocks have independent and nonidentical uncertainty distributions, respectively. The parameters in the distributions are uncertain variables. The belief reliability function and the mean time to failure of the system under three different shock models are studied according to uncertainty theory, and Micro-Electro-Mechanical System as an example is used to explain the developed models.