Reliability estimation and preventive maintenance for complex multi-component systems subject to multiple dependent competing failure processes

Some complex systems experience multiple dependent competing failure processes, and many traditional approaches to reliability are inadequate or inappropriate because there are two or more dependent/correlated failure processes and multiple components subject to failure. A typical design example representative of these systems is Micro-Electro-Mechanical Systems. The dependency among the failure processes and the dependency among the component failure times present challenging issues in reliability modeling. In reality, for many actual engineering problems, there are interactions between soft failure and catastrophic failure that should not be ignored. Also, interaction among components should be considered. This paper develops a new reliability model and optimal preventive maintenance policies for complex multi-component systems experiencing multiple failure processes due to simultaneous exposure to degradation and shock loads. The developed reliability and maintenance models are demonstrated for a multicomponent systems example. These models can also be applied directly or customized for other complex systems that experience multiple dependent competing failure processes.