Planning and scheduling efficient heavy rail track maintenance through a Decision Rules Model

Abstract

The most advanced preventive maintenance for railway track relies strongly on inspection and deterioration assessment to provide a given prediction for a maintenance need. Maintenance of track sections is then decided based on long-term planning for an extended track life and on short-term scheduling, combining maintenance tasks, to reduce the number of track possessions. In the particular case of track geometry correction (TGC), which requires moving costly heavy equipment and specialized crews working over-night, a large outlay is involved as well as relevant track possession costs. However, to the best of our knowledge, no research has yet addressed a combined tactical and operational analysis over the determinant logistics issue involved in the problem. In this sense, we propose a method to plan and schedule the heavy maintenance interventions for TGC, where both travel costs and number of workdays spent on track are minimized, ensuring at the same time, an adequate quality for the track.The method follows a Decision Rules Model (DRM) which is able to provide planning/scheduling solutions by following a set of rules used in maintenance practice. A resolution algorithm that reproduces the optimal solving is developed, whose formulation was established previously. The DRM is able to reach solutions for annual periods with significant reductions in the unit maintenance cost. The method is best applied in the consideration of regular work intensities and, observing a real case of a 300 km double track line, it was possible to conclude that the problem can be reduced to the determination of the frequency of the number of traverses of the complete line (required for maintenance) that ensures the minimum maintenance cost for a given temporal horizon.