Q/T Calculations

The quantitative FTA evaluation now supports the industry best-practice for calculating Q/T (i.e. unavailability over mission time) considering event dormancies. The computation comes with two flavors for average and worst-case exposures, e.g. to show means of compliance in Aerospace certifications and ARP 4761(A).

TRUE/FALSE Probability Model

In addition to the probabilistic event model 2022 R1 introduces a pure boolean TRUE/FALSE model. This allows e.g. to toggle branches on/off, enabling users to model multiple configurations in a fault tree or describe events that are just inserted for documentation purpose.

Improved mission time handling

In conjunction with the Q/T calculations the handling of mission time has been improved so that an evaluated fault tree stays consistent while updating the mission time e.g. for another FTA model. Note that this takes effect only after you re-computed your fault trees with the new version.

Probability cut off

An additional probability truncation option is now available to reduce cut sets to only relevant ones. This option works as filter on the cut sets and after the (exact) top event probabilities have been determined so that you'll experience no drawback in dropping cut sets.