Performability Evaluation of Railway Systems: A Study on the Impact of Adding Alternative Routes

Railway systems require high performance, availability and reliability, in addition to safety and maintainability as attributes for the implementation of equipment responsible for signaling, control, and traffic of trains on the railway. Studies are necessary to deal with these essential requirements for the quality of rail systems. This article proposes a set of models in stochastic Petri nets to evaluate the impact of adding alternative routes on performance and availability indicators in railway systems. Metrics such as travel time, the interval between trains, and passenger waiting time at stations were collected and analyzed to estimate the impact of such metrics on railway systems. This work also presents case studies that simulate the implications of the availability of signaling and train control equipment on the performance of a railway and demonstrate the versatility of the proposed model in allowing the insertion of stations and varying the number of trains in the studied railway network. The results obtained demonstrate that the availability of the studied system can be increased from 81,674% to 98,456%.