SYSML12 — Port Decomposition of a Flow Specification Discussion

Port Decomposition of a Flow Specification Discussion. There has been continued need to be able to decompose ports. One approach is to decompose a flow specification. In order to more readily accomplish this, a flow specification steretoype should subclass block instead of extending interface. This would enable many of the block constructs to be used, such as nested connector ends, the dot notation, and other features. A nested connector ends would allow direct connections to the flow properties of flow specifications. Dot notation could be applied to refer to the flow properties. In addition, to enable further levels of decomposition, a flow property should be able to be typed by a Flow Specification. The notation should also be clarified to allow for flow ports typed by flow specifications to show the port with the nested flow properties, and futher levels of nesting as required. As an additional comment, a connector to the port that is typed by the flow specification can be allocated to sub connectors that connect directly to the flow properties to support the concept of connector decomposition. Recommendation. 1. Modify Figure 9.1 to show the Flow Specification stereotype subclassing block rather than extending Interface. 2. Modify Flow Property in 9.3.2.4 to allow it to also be typed by a Flow Specification. This should be reflected in the Description and Constraint 1. 3. Modify Flow Specification in 9.3.2.5 to note that Flow Specifications can be decomposed (not sure this is necessary, but it might be good to clarify). 4. Modify the text for the diagram extension to flow port in 9.3.1.1 to describe that a flow port that is typed by a flow specification can be notated with the port symbol that nests the flow properties. Also note that a connector can connect directly to these flow properties using nested connector ends, and that the dot notation can be applied to refer to the flow properties. Finally, note that flow properties can be nested more than one level.

This issue is resolved by loosening UML constraints on connectors to enable
thems to connect to ports nested on ports, recursively, and provide a notation for
nested ports. It clarifies that item flows can be typed by association blocks
containing connectors between nested ports. Issues 10059, 11628, 12914, and 14086 are also resolved, see those issues for
more information.