A hybrid maintenance policy for a deteriorating unit in the presence of three forms of variability
针对退化路径受时间变异性、单元间变异性和测量误差影响的单元，提出了一种混合基于状态和基于时间的维护策略，使用带随机效应的伽马模型描述隐藏退化过程。
In this paper, a hybrid condition-/age-based maintenance policy is proposed for deteriorating units whose observed degradation paths are affected by temporal variability, unit to unit variability, and measurement error. The hidden degradation process is described by using a gamma model with random effect. The measurement error is modeled as a non-Gaussian random variable. Units are assumed to fail when their degradation level exceeds a given threshold.