GSN Metamodel

Updated GSN meta-model for GSN Standard Version 2 (Metamodel v2.2) is available here

GSN Metamodel Overview
The document provides a metamodel for the core GSN as defined in Version 2 of the GSN standard.

The GSN metamodel is defined by extending the Structured Assurance Case Metamodel (SACM) - a standard specified and maintained by the Object Management Group (OMG).

The definition of the GSN metamodel allows modelers to create GSN models that can be exchanged among modelling tools. It should be noted however that the class diagrams shown in the document depict the abstract syntax of GSN. This abstract syntax needs to be made concrete in order to be comprehended by humans (or computers). The graphical notations defined in the GSN standard are the concrete syntax of the abstract syntax defined in this metamodel. The concrete syntax enables GSN models (created using this metamodel) to be represented as GSN diagrams.

The definition of the GSN metamodel involves extending elements (concepts) in SACM, as well as defining additional constraints to disable elements that are not used in the context of GSN and are therefore not to be included in GSN models.

It should be noted that the constraints discussed in the document are only those applicable to models created using the GSN metamodel. There is an additional set of constraints related to creating valid GSN arguments (i.e. through the use of GSN graphical notations); these constraints are discussed in the GSN standard and not in this document as they are not related to the definition of the GSN metamodel itself. 
 

The original V1 mapping of GSN to SACM 2.1 is available (here) and (here)