Asset Management of Railway Tracks Using Stochastic Petri Nets

Sammanfattning: Railways are one of the most important transport systems. It is crucial to have a rail network that is safe, reliable and available. Asset Management for railways involves the optimization of the maintenance activities based on asset condition, life cycle cost and availability of equipment. Irregularities in the track cause the wear of rail resulting in passenger discomfort, speed restrictions and line closures. The track is inspected for these irregularities and corrected using a tamping vehicle. The degradation behavior of the track can be modelled to predict the future degradation. This prediction forms the basis of the maintenance planning based on the expected track condition. A petri net model can be used to simulate the track degradation, inspection and maintenance process over a period of 20 years, and the outputs of the model are used for LCC analysis. Further, the cost is optimized with the safety risk to suggest maintenance threshold levels and Inspection Interval. The proposed methodology will assist the maintenance decision system for Asset Management of Railway track, which is strategic and cost effective. This methodology is demonstrated using a case study of a Line 414 in Sweden, by modelling the track behavior with Standard Deviation of Longitudinal Level. It can be further expanded and adapted for maintenance planning for similar assets within railways.