Efficient Analysis Algorithms for Parametric Fault Trees

The Fault Tree (FT) is a widespread model for the dependability (reliability) analysis. One of its several extensions is called Parametric Fault Tree (PFT) and is oriented to redundant systems providing a compact (parametric) way to model replicated components or subsystems. This paper presents the PFT solution method based on a new form of Binary Decision Diagrams (BDD), called Parametric BDD (pBDD). Such method exploits the parametric form combined with the advantages of the use of BDDs. pBDDs are used for both the qualitative and the quantitative analysis of PFTs. A case of redundant system supports the introduction and the application of the new method.