Stochastic Petri Nets and inheritance for dependability modelling.

Reuse is a well-known and widely accepted principle in design and programming, that is instantiated through two main means: modularity and inheritance. Modularity allows a function or a data type and associated functions to be reused, while inheritance is based on the idea that a set of common features of a type can be factorized into a common supertype. While modularity has been widely exploited in performance and dependability modelling, inheritance is instead pretty much a "still-to-investigate" topic for this field. We discuss the role of inheritance in stochastic Petri nets (SPN) modelling, by considering a representation of the fault, error, and failure (FEF) chain based on hierarchies of classes (in the class diagram formalism of UML) and corresponding hierarchies of SPN models.