Coherent systems with components subject to additive or multiplicative degradation models

This paper aims to develop a general framework to use degradation models in the reliability assessments of coherent systems. In the first part of the paper, we prove that if the components of a system are subject to a degradation model, then the same holds for the system. This fact is used to study the preservation results of some aging classes and stochastic orders in systems under degradation models. In the second part, we give a survival signature-based representation of the system’s reliability under the condition that the components of the system deteriorate under a linear degradation model. We then use this representation of the system’s reliability to propose optimal preventive maintenance for coherent systems whose components are under a linear degradation model.