Reliability Modelling of ERTMS/ETCS
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System reliability analysis has a significant influence on making decision and defining requirements for future operations. Performing a reliability assessment for a complex system is challenging due to varied performance of different sub systems. European Railway Traffic Management System/ European Train Control System (ERTMS/ETCS) is a similar complex system addressed in the thesis for developing a reliability model and its assessment. In order to implement the modelling of ERTMS/ETCS, an existing line operating on ERTMS level 2 is chosen as case study from Bane NOR. Since all the railway projects are implemented according to the railway standards, a general overview of these standards and the importance of RAMS is elaborated. A literature review is then performed to identify suitable methods for reliability modelling practiced in general railways and ERTMS. On performing a thorough assessment of the literature, a multi formalism modelling approach is proposed for modelling the Østfoldbanen Østre Linje (ØØL) ERTMS pilot line as a case study. As a part of multi formalism modelling, different conventional methods are applied initially and then simulations are performed using software programs to assess reliability. Primarily reliability block diagram method is used to model the ØØL line in Relysim software with a combination of single station and bidirectional (BiDi) section, and then 1000 simulations are conducted to assess ØØL ERTMS infrastructure. It is estimated from Relysim results that this model has the potential to determine the performance of the infrastructure. From Relysim model it is deduced that predominant infrastructure failures that cause delays are due to partial interlocking fail, maintenance and track fracture, followed by failure of balise, axle counters and points. Later a software developed by DNV GL called TRAIL is used for modelling, in which a usage based model is implemented at first based on the historical data of delays in 2016. The data is distributed to all stations and BiDi sections and simulated for 100 annual runs. Secondly, a time-based model is developed in TRAIL with inputs as infrastructure, reliability parameters, system dependency, timetable, routes etc. and again performed 100 annual simulations to estimate the reliability and punctuality. From TRAIL models simulation, reliability and availability of ERTMS infrastructure present at stations and BiDi sections of ØØL pilot line is estimated along with the sections criticality. Additionally, the overall availability and punctuality of the train services operating on the ØØL pilot line is also measured. The time based model in TRAIL is found to be more practical due to the fact that it considers all the constraints and the model is validated by comparing its results with usage based model results. Since all the models are developed with several assumptions and some uncertainty, suggestions are given for further research to Bane NOR and TRAIL in light of reliability modelling of ERTMS/ETCS.