Performing the Analysis

FaultTree+ in Reliability Workbench provides CCF analysis, importance analysis, uncertainty and sensitivity analysis facilities. FaultTree+ uses efficient minimal cut set generation algorithms to analyze large and complex fault and event trees. NOT logic may be included in the fault and event trees at any level and event success states retained in the analysis results as an option.

After performing the analysis the Results Summary dialog (shown below) provides a detailed overview of the analysis results.

The comprehensive reporting facilities are also included, allowing the user to report on their results using sophisticated text, graph and diagram reports.

Fault Tree Analysis Features

  • Range of event failure and repair models including fixed rates, dormant, sequential, standby, time at risk, binomial, Poisson and initiator failure models
  • Basic events may be linked to Markov models created in the Markov analysis module
  • CCF analysis using the beta factor, MGL, alpha factor or beta BFR methods. Initiator-enabler analysis for sequence dependent analyses
  • Sensitivity analysis allowing the automatic variation of event failure and repair data between specified limits
  • Time dependent analysis providing intermediate values for time dependent system parameters. Verification checks providing diagnostic information before commencing an analysis. Checks are made for circular logic, undefined gates, invalid initiators etc.
  • Fault tree house event analysis. Full minimal cut set analysis (including success states if required)
  • Post-processing facilities for accurate upper bound calculations. Importance analysis with Fussell-Vesely, Birnbaum, Barlow-Proschan and Sequential importance measures. Risk measures provided for event tree consequences.
  • Uncertainty analyses allowing confidence levels to be determined from event failure and repair data uncertainties. Status facility to indicate whether analysis results are out of date with respect to project data.