SACM — Incorporate 9.1.1 Assertion (p30) in a coherent way into merged SACM metamodel

Incorporate 9.1.1 Assertion (p30) in a coherent way into merged SACM metamodel

All references are against document ptc/2012-04-04
Change the description of the Assertion element, section 12.1.1, pages 50-51 into:
An Assertion is a relationship involving one or more formal objects, taken as formal
proposition that has a distinct, separate existence, a self-contained piece of information
that can be referenced as a unit. Assertion is the key constituent of a conceptual model
underlying the assurance case. Assertion represents an asserted fact about the subject area
for which the assurance case is being developed.
Superclass
FormalAssertio
Attributes
• facctype:String Designation of the fact type
Associations
• role:RoleBinding[0..*] Set of role bindings that further describe which
DomainObject are bound to the roles that are determined by the fact type.
• definition:MOF::Element A link to an entry of an external SBVR vocabulary or
an OWL ontology defining the fact type of the assertion.
Semantics
Assertion is an element of meaning that states existence of a relationship between several
individual formal objects. In a formal assurance case, the nature of the relationship is
specified through a reference to an external vocabulary, such as an SBVR vocabulary or
an OWL ontology. SACM assumes that the community of interest for the assurance case
will acquire or develop such vocabularies for the corresponding subject area. In a semiformal
assurance case the nature of the relationship can be described informally through a
'content' property. In this case the 'definition' property and the 'facttype' property shall not
be used. However the references to the exact FormalObjects through RoleBinding
elements can be still stated. The 'content' property of the FormalAssertion element
provides the verbalization of the assertion, in the form of an expression of the assertion in a selected natural language. For informal assurance cases, a ReferencedClaim element
can be used, which only contains the verbalization of the claim in a natural language.