| dc.description.abstract | Recently in Taiwan, the Mass Rapid Transit (MRT) system has been greatly expanded, gradually becoming the main form of urban transportation in the region. To ensure the stable and normal operation of the MRT system, it is necessary to take advantage of limited resources to conduct a well-scheduled maintenance plan that can effectively and efficiently carry out facility maintenance work. Currently, MRT facility maintenance scheduling is mainly planned by maintenance staff, rely on past experience. However, the manual adjustment method, which uses a trial-and-error approach, is neither systematic nor efficient. Furthermore, when facility failure occurs during regular operations, maintenance personnel must be dispatched urgently to troubleshoot, repair, and inspect the facility to minimize the impact on regular MRT operations. Repair work often requires assigning maintenance staff to carry out repairs and can require significant adjustments to the previously planned maintenance schedule. In the first part of this thesis, the time and space network flow technique is used to create a systematic and efficient weekly maintenance schedule for MRT facilities. This model takes into account the estimated demands for repair works, regular preventive maintenance needs, and existing manpower constraints, including the certified maintenance staff requirements. Furthermore, to improve the maintenance performance and reduce the cost of maintenance, a strategy has been developed that involves requiring maintenance staff belonging to the same plant to carry out emergency maintenance work to minimize the overall maintenance cost.
In current practice, the head of each maintenance subsection or deputy is responsible for planning the daily maintenance schedule for their group. This includes preventive maintenance based on known regular recurring maintenance items, as well as troubleshooting to plan repairs for faulty facilities that require attention on the day the schedule is made. They also have to take into account the available self-owned maintenance manpower, supporting resources from outsourced contractors, and other relevant factors. In the second part of this thesis, we apply the network architecture developed in the first part to develop a daily maintenance rescheduling model. This model considers the needs identified from repair works in the daily maintenance schedule and has the objective of minimizing maintenance costs and reducing the variance of scheduled works for the next day. To better align with practical needs, a strategy for sharing repair work across different maintenance teams within the same section has been developed. In addition, the model takes into account quantity restrictions, which allow maintenance teams to work simultaneously at the same site.
In this thesis, we develop two models: a weekly maintenance scheduling model and a daily maintenance rescheduling model and apply the network flow concept to represent the movement of MRT maintenance team. Additionally, to efficiently solve the large and complex problem of weekly maintenance scheduling in the first part, we have developed a heuristic algorithm that applies a divide-and-conquer approach based on the maintenance day. In contrast, the scope of the daily maintenance rescheduling model is smaller and can thus be solved directly using mathematical programming software. After testing and verification through case studies, these models and the developed algorithm are useful for decision-makers in the MRT system in solving the problem of maintenance scheduling. | en_US |