Qingqing Zhai

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In many real-world applications, a mission may consist of several different tasks or phases that have to be accomplished in sequence. Such systems are referred to as phased-mission systems (PMS). In this paper we consider the demand-based PMS with parallel structure, where the system components function in parallel with different capacities in each phase of(More)
Importance measures have been widely studied and applied in reliability and safety engineering. This paper presents a general formulation of moment-independent importance measures and several commonly discussed importance measures are unified based on Minkowski distance (MD). Moment-independent importance measures can be categorized into three classes of MD(More)
This paper models repairable computing systems performing a mission that is successful if the system can accomplish a specified amount of work within the allowed mission time or deadline. During the mission the system is subject to a sequence of full and incremental data backup procedures to facilitate an effective system recovery and avoid repeating the(More)
Variance-based sensitivity analysis has been widely studied and asserted itself among practitioners. Monte Carlo simulation methods are well developed in the calculation of variance-based sensitivity indices but they do not make full use of each model run. Recently, several works mentioned a scatter-plot partitioning method to estimate the variance-based(More)
This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of(More)
Optimal component order can effectively improve the system reliability for the design of a warm standby sparing (WSP) system. The optimal component order in the 1-out-ofWSP system is studied in this paper. The optimal component order strategies in terms of the expected system lifetime are proposed, and proved for several cases. Furthermore, the 1-out-ofWSP(More)