title: Movares - model-based risk analysis for train systems
company: Movares
keywords: fault tree analysis, failure rate, basic events, tolerable hazard rate
committee: Mariëlle Stoelinga


Movares is a consulting company that performs risk assessments for its customers, including ProRail, Rijkswaterstaat, and many others. 

Fault Tree Analysis (FTA) is a popular technique to model and analyze the risks associated to complex infrastructures, for example railroads, tramways, and waterworks (eg the Maeslantkering in Rotterdam).

Traditionally, FTA techniques are bottom up: they calculate the risk (i.c. failure probabilities) of the system from failure probabilities of its components.

For Tolerable Hazard Rate (THR) analysis, the direction of the calculation is reversed: the maximal failure rate of the top event is fixed (eg the maximal probability of failure is 0.5% per year), and we want to derive the maximal failure rates are for the system components.

An example of such a THR analysis for an automatic train protection system: given the maximal number of casualties per year and the functionality of the system, determine per safety function how often it may fail.

The goal of this internship project is to develop THR techniques and implement these in a given FTA program (to be determined: Isograph FaultTree , Open FTA or CORAL) such that it can perform such a top-down calculation.


  1. UT Course “Quantitative modelling & analysis (QMA)”
  2. NEN-EN-IEC 61025:2007 Fault tree analysis (FTA)