Heuristic Techniques for Scheduling Railway Track Maintenance

Abstract

The maintenance of a rail network significantly contributes to the total cost of operating the network. Therefore substantial savings in railway expenditure can be achieved if track maintenance is conducted in the most cost-effective manner. Railways, however, operate under the conflicting objectives of minimising the infrastructure expenses while continuing to provide adequate service. This paper reports on the development of a model for the short-term scheduling of track maintenance activities, after the train schedule and maintenance activities have been planned. The model schedules the track maintenance activities, including assigning the maintenance crews to the activities, with the objective of minimising the total maintenance costs. This maintenance scheduling model has been solved using a two stage heuristic technique, with the first stage generating a feasible solution and the second stage implementing one of simulated annealing, local search or tabu search. The paper presents the results of applying the model to a problem that is indicative of the size experienced in the railway industry, with twenty track segments and a seven-day scheduling period. The three heuristic methods are then compared for the solution values obtained and the time frame required.