Reliability Analysis of Phased-Mission Smart Home Systems With Cascading Common Cause Failures

With the ability to produce renewable energy sources and control system devices in an adaptive way, smart home systems (SHSs) have significantly improved the quality of our lives. Due to the mission-critical nature and the complex correlations within the system, it is imperative to perform reliability analysis on SHSs. This article studies the reliability of SHSs performing multiphase mission and subject to both common cause failures and cascading behaviors, where the occurrence of common causes would cause failures of multiple components and the failure of a component may further affect other system components in a domino chain manner. In this article, we propose a multivalued decision diagram-based method to assess reliability of phased-mission SHS with cascading common cause effect. The proposed method, applicable to arbitrary time-to-failure distributions, is generalized to reliability analysis of SHSs with multiple repeated operation cycles. Both space and computational complexities of the proposed method are discussed; the correctness is verified using the Monte Carlo simulation method. A detailed case study on an SHS example is performed to illustrate the application and advantages of the proposed method. A sensitivity analysis is carried out to examine the contribution of each component failure to the overall failure of the example SHS.