UAF13 — PropertySet - Incorrect Definition, Specialisation Short Circuits Metamodel - 'System PropertySetGeneralization Viewpoint' etc. Triples Not in any UAF Architecture View

p245 9.1.12 Domain Metamodel::Parameters - PropertySet & Fig 9:363

PropertySet is defined as 'An abstract type grouping architectural elements that can own Measurements.'

1) Incorrect. The definition is not atomic - refers to 'owns' which implies a relationship that isn't present with PropertySet in the metamodel. 'Architectural Element' is actually an AD element (cf ArchitecturalReference). Things don't own measurements - they have characteristics that are quantified by measurements. The definition should only define the concept not the use or application of the element - this would then highlight the problem wrt what the concept actually represents. It appears to be an implementation artefact that has nothing to do with the fundamental metamodel concepts.

2) Figure 9:363 shows that many metamodel elements specialise PropertySet, most of which are semantically incorrect. We have, for example, 'System is a PropertySet', 'Viewpoint is a PropertySet', 'StrategicPhase is a PropertySet', 'OperationalInterface is a PropertySet'. The full class hierarchy needs to be shown including all types of Asset, Resource and MotiovationalElement otherwise the sense (or error) of what is being asserted cannot be verified. The only assertion that is probably correct is 'MeasurementSet is a PropertySet'

3) There is a reflexive PropertySetGeneralization on PropertySet - presumably to assert a specialisation of successive PropertySets. However, because it is on PropertySet - the parent - and because the child elements inherit this relationship with any PropertySet element it therefore asserts that 'System PropertySetGeneralization Viewpoint', 'EnterpriseGoal PropertySetGeneralization Service' i.e. the child PropertySet elements can be connected together using PropertySetGeneralization which is semantically meaningless.

4) There are several elements - possibly many - where a triple including PropertySetGeneralization can never appear in any architecture view (doesn't appear in the definition of allowed content of any 'view specification'). For example the View, Viewpoint elements. You might expect these particular triples to appear in the Summary & Overview 'view specification' if valid - but there is nothing shown in 8.1.2 and doesn't address the concerns. If triples do not address concerns and do not appear in any 'view specification' they should be deleted from the metamodel - they serve no defined purpose.

5) There is no defined relationship between Measurement and PropertySet that can be used in any 'view specification' - this would require a relationship element to be shown and there is only the reflexive PropertySetGeneralization