SYSML16 — Abstract syntax for the initial values

The abstract syntax supporting the specification of initial values for properties of SysML block has to be clarified and aligned with the intended semantics.

In SysML 1.4, §8.3.1.2.8 says: “A compartment with a label of “initialValues” may be used to show values of properties belonging to a containing block.

These values override any default values that may have been previously specified on these properties on their originally

defining block”

While §8.3.2.3 says: “An entire tree of context-specific values can be specified on a containing block to carry values of nested

properties as shown on an internal block diagram”, then: “If a property belonging to a block has a specification of initial values for any of the properties belonging to its type, then

the default value of that property must be a UML InstanceValue element. This element must reference a UML

InstanceSpecification element created to hold the initial values of the individual properties within its usage context. The

instance specification must be unnamed and owned by the same package that owns the outermost containing block for

which the initial values are being specified”

If the specification of an initial value is “context specific”:

· It cannot be specified using the default value of a property

· It should be possible to distinct initial value depending on the context, i.e. we need a resolution mechanism to know which initial value has to be used

Defer

Postponed to the next RTF