Large fleets of engineering assets that are subject to ongoing degradation are posing the challenge of how and when to perform maintenance. For a given case study, this paper proposes a formulation for combined scheduling and planning of maintenance actions. A hierarchical approach and a two-stage approach (with either uniform or non-uniform time grid) are considered and compared to each other. The resulting discrete-time linear programming model follows the Resource Task Network framework. Asset deterioration is considered linearly and tackled with an enumerator-based formulation. Advantages of the model are its computational efficiency, scalability, extendability and adaptability. The results indicate that combined maintenance planning and scheduling can be solved in appropriate time and with appropriate accuracy. The decision-support that is delivered helps the choice of the specific maintenance action to perform and proposes when to conduct it. The paper makes a case for the benefits of optimally combining long-term planning and short-term scheduling in industrial-sized problems into one system.

不断退化的大型工程资产船队对如何以及何时进行维护提出了挑战。对于给定的案例研究，本文提出了维护计划的联合计划和计划的表述。考虑并比较了分层方法和两阶段方法（具有统一或不统一的时间网格）。产生的离散时间线性规划模型遵循资源任务网络框架。线性考虑资产恶化，并使用基于枚举数的公式解决。该模型的优点是其计算效率，可伸缩性，可扩展性和适应性。结果表明，可以在适当的时间以适当的精度解决组合的维护计划和计划。提供的决策支持有助于选择要执行的特定维护措施并建议何时执行。本文提出了将工业规模问题中的长期计划和短期计划最优地组合到一个系统中的好处。