Reliability of warm-standby systems subject to imperfect fault coverage

This article models and analyzes the reliability of warm-standby systems subject to imperfect fault coverage based on sequential multistate decision diagrams. For warm-standby systems, the standby units have different failure rates before and after they are used to replace the online faulty unit. Furthermore, a component fault may propagate through the system and cause the entire system to fail if the fault is uncovered or undetected due to the imperfect system recovery mechanism. Existing works on warm-standby systems with imperfect fault coverage are restricted to some special cases, such as cases assuming an exponential time-to-failure distribution for all the system components or cases considering only one warm spare unit. The proposed sequential multistate decision diagram-based approach can overcome the limitations of the existing approaches. Examples are given to illustrate its advantages and applications.