Fault Tree Analysis¶
Use ATICA to create a fault-tree top event, build its diagram, calculate probabilities, inspect cut sets, and reuse branches through transfer gates.
Architecture layers¶
Fault Tree Analysis can be performed in Capella's System Analysis, Logical Architecture, and Physical Architecture layers. A fault tree can also interconnect failure information across these layers; its events do not need to belong to a single architecture layer.
For example, a failure condition in System Analysis can use either of the following as a base event:
- a functional failure from Logical Architecture;
- a physical failure mode from Physical Architecture.
This cross-layer structure connects the higher-level failure condition to the contributing logical and physical failures in the Capella model.
Calculation engine¶
The FTA calculation engine is built into ATICA. No connection to an external calculation service or tool is required. ATICA calculates fault-tree probabilities using combinatorics and the inclusion–exclusion principle. Repeated events in a fault tree are considered and handled correctly by the calculation.
The calculation engine has been validated through controlled tests. Its results can also be demonstrated against different client test cases.