Reliability analysis for k-out-of-n systems subject to multiple dependent competing failure processes

A new k-out-of-n redundancy system is studied where all components have the same characteristics and experience dependent failure processes due to simultaneous exposure to degradation and shock loads. The k-out-of-n system reliability model is developed and preventive maintenance policy is applied. Some research has been done on a single component or simple system, or systems with independent failure times and failure processes. This new model extends previous research by considering degrading components within a k-out-of-n system with dependent failure processes. Failure times for all components are probabilistically dependent. Each component can fail due to a soft failure process or a hard failure process. The failure processes are mutually competing since either failure process can cause the component to fail. The failure processes are also dependent since the arrival of each shock affects both failure processes for all components. An age replacement policy is applied for this system. Optimal replacement interval is determined by minimizing a cost rate function.