Wheelsets absorb a significant part of the maintenance budget of any train operating company. Although wheel wear has been an extensively discussed topic in the literature, wear rates are very rarely characterized by using degradation data in a real‐world case study aimed at identifying optimal maintenance policies including both degradation and recovery modeling. Furthermore, wheel defects, which impose an additional challenge to the modeling of the lifecycle of the wheels, are usually considered separately in the literature. In this study, conducted at a Portuguese train operating company, 17 years of inspection data are used to estimate wheel wear rates and survival curves, which are further incorporated into a Markov decision process (MDP) model. A bidimensional framework considering discrete intervals of wheel diameter along with a quantitative variable (kilometers since last turning/renewal) is used to represent the possible wheel states, while the probability of a defect interfering with the wheel maintenance schedule is modeled by contemplating survival curves derived from a Cox proportional‐hazards model. Optimal results in terms of minimal cost policy are discussed in the context of the MDP, but a more realistic and easy‐to‐implement policy fixing one of the parameters is compared with the optimal policy. Results showed that in practice train operating companies might benefit from using the easy‐to‐implement policy, which has an associated long‐run average cost only about 1% higher than the one suggested by the optimal decision map.

中文翻译：

---

基于生存分析和马尔可夫决策过程的铁路轮对数据驱动维修策略

轮对占用任何火车运营公司的维修预算的很大一部分。尽管轮毂磨损一直是文献中广泛讨论的话题，但在实际案例研究中，很少使用退化数据来表征磨损率，该案例旨在确定最佳的维护策略，包括退化和恢复模型。此外，通常在文献中单独考虑轮缺陷，这对轮的寿命周期的建模提出了额外的挑战。在葡萄牙火车运营公司进行的这项研究中，使用了17年的检验数据来估算车轮磨损率和生存曲线，并将其进一步纳入马尔可夫决策过程（MDP）模型。考虑车轮直径离散间隔和定量变量（自上次转向/更新以来的公里数）的二维框架用于表示可能的车轮状态，而缺陷干扰车轮维护进度的可能性则通过考虑得出的生存曲线来建模来自Cox比例风险模型。在MDP的背景下讨论了基于最小成本策略的最优结果，但是将固定参数之一的更现实，更易于实现的策略与最优策略进行了比较。结果表明，在实践中，火车运营公司可能会受益于使用易于实施的策略，该策略的长期平均成本仅比最佳决策图建议的成本高约1％。