Reliability for systems of degrading components with distinct component shock sets

• Published in: Reliability engineering & system safety Vol. 132; pp. 115 - 124
• Main Authors: Song, Sanling, Coit, David W., Feng, Qianmei
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2014; Elsevier
• Subjects: Applied sciences; Component shock set; Degradation; Exact sciences and technology; Failure; Fundamental areas of phenomenology (including applications); Industrial metrology. Testing; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Intervals; Maintenance; Mathematical analysis; Mathematical models; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Multiple dependent competing failure processes; Operational research and scientific management; Operational research. Management science; Physics; Policies; Preventive maintenance; Random shocks; Reliability theory. Replacement problems; Sensitivity analysis; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Degradation; Multiple dependent competing failure processes; Component shock set; Random shocks; Preventive maintenance; Costs; Sensitivity analysis; Probabilistic approach; Competing risk; Complex system; Maintenance; System reliability; Failures; Modeling; Optimization; Break up time; Manufacturing defect; Wear; Dependence; Random load; Microelectromechanical device; Mechanical shock
• DOI: 10.1016/j.ress.2014.06.020
• ISSN: 0951-8320

This paper studies reliability for multi-component systems subject to dependent competing risks of degradation wear and random shocks, with distinct shock sets. In practice, many systems are exposed to distinct and different types of shocks that can be categorized according to their sizes, function, affected components, etc. Previous research primarily focuses on simple systems with independent failure processes, systems with independent component time-to-failure, or components that share the same shock set or type of shocks. In our new model, we classify random shocks into different sets based on their sizes or function. Shocks with specific sizes or function can selectively affect one or more components in the system but not necessarily all components. Additionally the shocks from the different shock sets can arrive at different rates and have different relative magnitudes. Preventive maintenance (PM) optimization is conducted for the system with different component shock sets. Decision variables for two different maintenance scheduling problems, the PM replacement time interval, and the PM inspection time interval, are determined by minimizing a defined system cost rate. Sensitivity analysis is performed to provide insight into the behavior of the proposed maintenance policies. These models can be applied directly or customized for many complex systems that experience dependent competing failure processes with different component shock sets. A MEMS (Micro-electro mechanical systems) oscillator is a typical system subject to dependent and competing failure processes, and it is used as a numerical example to illustrate our new reliability and maintenance models.