Solving dynamic flowgraph models with FinPSA

Research output: Book/ReportReport

Abstract

Dynamic flowgraph methodology (DFM) is a method for the reliability analysis of dynamic systems with time-dependencies and feedback loops. A DFM model is a graph representation of the analysed system, and its components are analysed at discrete time points and they can have multiple states. The aim of DFM is to identify which conditions can cause a top event, e.g. the system's failure. The reason for the development of DFM is that traditional methods, such as fault tree analysis, can describe the system's dynamic behaviour only in a limited manner. DFM can more accurately represent the system's evolution in time. VTT has previously developed a DFM tool called Yadrat, which solves a DFM model by transforming it into a binary decision diagram. It has however not been possible to apply Yadrat to large systems. To improve Yadrat's computational capacity and to reduce computation times, this report studies an alternative way of solving a DFM model. A DFM model is transformed from Yadrat into the fault tree format of the probabilistic risk assessment (PRA) software FinPSA, then solved by the fault tree algorithm of FinPSA. To make this possible, FinPSA's fault tree algorithm has been developed to take into account the non-coherent logic of DFM. A simple DFM model has been solved correctly using FinPSA. However, with the preliminary implementation it has not yet been possible to solve more complex models correctly. Therefore, there has not been a possibility to evaluate the computational efficiency of the implementation yet. The next step is to resolve the issues conserning the computation of larger models. Then, FinPSA implementation can be benchmarked with Yadrat to find out whether FinPSA is faster and able to solve large models.
Original languageEnglish
PublisherVTT Technical Research Centre of Finland
Number of pages14
Publication statusPublished - 2017
MoE publication typeD4 Published development or research report or study

Publication series

SeriesVTT Research Report
VolumeVTT-R-04628-17

Fingerprint

Dynamic models
Dynamical systems
Binary decision diagrams
Fault tree analysis
Reliability analysis
Computational efficiency
Risk assessment
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Keywords

  • dynamic flowgraph methodology
  • fault tree
  • FinPSA

Cite this

Tyrväinen, T. (2017). Solving dynamic flowgraph models with FinPSA. VTT Technical Research Centre of Finland. VTT Research Report, Vol.. VTT-R-04628-17
Tyrväinen, Tero. / Solving dynamic flowgraph models with FinPSA. VTT Technical Research Centre of Finland, 2017. 14 p. (VTT Research Report, Vol. VTT-R-04628-17).
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Tyrväinen, T 2017, Solving dynamic flowgraph models with FinPSA. VTT Research Report, vol. VTT-R-04628-17, VTT Technical Research Centre of Finland.

Solving dynamic flowgraph models with FinPSA. / Tyrväinen, Tero.

VTT Technical Research Centre of Finland, 2017. 14 p. (VTT Research Report, Vol. VTT-R-04628-17).

Research output: Book/ReportReport

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Tyrväinen T. Solving dynamic flowgraph models with FinPSA. VTT Technical Research Centre of Finland, 2017. 14 p. (VTT Research Report, Vol. VTT-R-04628-17).