Designing a centralised model to value balance between aircraft uptime and downtime from an integral airline perspective: a case study at KLM E&M

This research aim was to design a centralised model that redefines definitions, standardises maintenance by categorisation, and reduces waste by introducing new slot lengths, leading to an equilibrium between flights and maintenance. This equilibrium enhances the airline’s capacity to manage maintenance efficiently and ensures greater uptime....

Railway - Spare Inventory & Maintenance Scheduling model development

To better govern inventory control of spare parts in tandem with scheduling of maintenance operations in a railway setting, a Railway Spare Inventory & Maintenance Scheduling (R-SIMS) model is developed. To suit the railway industry setting the model includes an inventory control strategy which envokes continuous monitoring and a reorder...

Optimization of the short-term labor and task scheduling in the maintenance of regional trains

The Dutch Railways (NS) is the Dutch national passenger railway operator. They own rolling stock that has to be maintained regularly. One of the maintenance facilities executing regular maintenance on regional trains is the maintenance department (OB) in Leidschendam. The aim of this project is to develop a framework for optimizing the...

A dynamic optimization model on the routing and maintenance scheduling of aircraft for individual tasks

Increasing competition amongst airlines necessitates them to improve the efficiency of their operations. Even though maintenance, repair, and overhaul (MRO) represent a significant portion of an airline’s operational costs, aircraft maintenance scheduling is often still a manual process, producing suboptimal solutions. Airlines typically operate...

Maintenance scheduling optimization based on prognostics and limited spare parts

The competition in the airline industry has rapidly increased during the last decades, especially with the entrance in the market of low-cost carriers. The high costs incurred in Maintenance, Repair and Overhaul (MRO) activities are generating a great interest in the improvement of maintenance operations as a way to stay competitive in the...

Work Task Order Optimization in Aircraft Hangar Maintenance: A Constraint-Based Heuristic Programming Approach

Scheduled aircraft maintenance consists of a set of work tasks to be executed. This thesis focuses on improving the order in which these work tasks are executed. Because finding an optimum for these kind of problems is computationally intensive, the chosen approach is of heuristic nature, which is a practical method resulting in close-to-optimal...

Constrained Multi-Aircraft Maintenance Scheduling Using Component Prognostics

In recent years, airlines have increasingly developed the ability to monitor the condition of aircraft components by means of sensors. In turn, aircraft maintenance aims to use this sensor data to predict component failures. However, the challenge remains to make use of these prognostics to generate appropriate maintenance schedules. In this...

Optimizing Long-Term Planning of Railway Maintenance

Railway maintenance is currently planned according to a fixed schedule, mostly of one year. This is usually not optimal when considering the cost of maintenance, of possessions and of failure. However, an approach that minimizes the sum of these costs was not yet available. This paper presents a statistical analysis method and an optimization...

Solving Train Maintenance Scheduling Problem with Neural Networks and Tree Search

The Train Maintenance Scheduling Problem (TMSP) is a real-world problem that aims at complete maintenance tasks of trains by scheduling their activities on a service site. Common methods of constructing optimal solutions to this problem are difficult as the problem consists of several highly-related sub-problems. Currently, NS is using a lo- cal...

Improving RCPSP algorithms using machine learning methods

For performing technical maintenance, it is important to keep a detailed schedule of resources and temporal constraints. The Resource Constrained Project Scheduling Problem (RCPSP) is a well de- fined scheduling model with both resources and temporal constraints. Precedence Constraint Posting (PCP) is a technique to solve the NP-hard RCPSP...