ConnectionUsage

Original XMI declaration. §7.13.2 Connection Definitions and Usages, printed 68 / PDF 100; §8.3.13.4 ConnectionUsage, printed 298 / PDF 330

What to understand

• A connection is a model element with end roles and references, even when drawn as a simple line.
• Nonabstract connections require at least two ends. Each end is referential with multiplicity 1..1; cross multiplicity is a separate concept.
• Allowed typing includes connection definitions and suitable KerML association structures.
• A structural connection is not interchangeable with a binding, succession or flow.

Graphical notation

These are representative, source-checked variants, not an exhaustive notation grammar. The illustrations are original redraws, not official figures.

Binary edge and connection node

Context: Structural connection representations.

A connection can use a solid binary line with an optional label, or a rounded full node labeled connection. The example omits the optional direction-indication arrow.

§8.2.3.13 Connections, printed 215 / PDF 247; §8.2.3.13 Connections, printed 216 / PDF 248

N-ary connection variant

Context: Connections with more than two ends.

The grammar also provides a central filled dot with segments to the connected usage nodes. It is an additional representation, not a universal replacement for binary lines.

§8.2.3.13 Connections, printed 216 / PDF 248

Relationships and composition

Specialization: PartUsage

ConnectionUsage directly specializes PartUsage as well as ConnectorAsUsage.

Condition: A connection therefore has inherited part properties, but adds connector end structure and applicable constraints.

§8.3.13.4, printed 298 / PDF 330

Endpoint reference: PortUsage

The example connects two port usages through qualified feature paths.

Condition: Retain the connection end declarations and their reference-subsetting semantics, rather than storing only a graphical line.

§7.13.2, printed 71 / PDF 103

Connected example

link is a named binary connection. Its ends refer to axle.mount and wheel.hub. The plain solid line is an illustrative connection representation, with no flow direction implied.

// Original documentation example. Source-reviewed; not parser-validated.
package AssemblyExample {
    port def Mount;

    part def Wheel {
        port hub : Mount;
    }

    part def Axle {
        port mount : Mount;
    }

    part def Assembly {
        part wheel : Wheel;
        part axle : Axle;
        ref part spare : Wheel[0..1];
        connection link connect axle.mount to wheel.hub;
    }

    part assembly : Assembly;
}

Verification: source-reviewed, not parser-validated or executed. §7.13.2 binary connection shorthand, printed 71 / PDF 103

Properties

The explicit-redefinition view contains 121 active declarations, retaining declaration origins and excluding 8 replaced declarations. It deduplicates diamond paths by identity, excludes private inherited fields, and reports unresolved same-name collisions instead of choosing a winner.

These are metamodel property cardinalities and declared defaults. They do not determine the multiplicity or runtime values of a part, port or connection in a user model. Derived values still require their derivation rules. See property rules.

Replaced declarations

• KerML::Core::Features::Feature::isVariable → SysML::Systems::DefinitionAndUsage::Usage::mayTimeVary
• KerML::Core::Features::Feature::type → SysML::Systems::Connections::ConnectionUsage::connectionDefinition, SysML::Systems::Occurrences::OccurrenceUsage::occurrenceDefinition
• KerML::Core::Types::Type::endFeature → KerML::Kernel::Connectors::Connector::connectorEnd
• KerML::Kernel::Connectors::Connector::association → SysML::Systems::Connections::ConnectionUsage::connectionDefinition
• KerML::Root::Elements::Relationship::relatedElement → KerML::Kernel::Connectors::Connector::relatedFeature
• KerML::Root::Elements::Relationship::source → KerML::Kernel::Connectors::Connector::sourceFeature
• KerML::Root::Elements::Relationship::target → KerML::Kernel::Connectors::Connector::targetFeature
• SysML::Systems::DefinitionAndUsage::Usage::definition → SysML::Systems::Occurrences::OccurrenceUsage::occurrenceDefinition

Reconciliation and limits

Seed reconciliation: SelectedFieldsMatch for direct bases, declared property names/types/bounds/derivation/ordering/subsets/redefinitions, constraint names. This checks selected structural fields only; it does not approve the entire seed or all semantics.

• This profile illustrates selected structural notations and does not implement execution or all association-structure semantics.
• Effective property resolution covers explicit inheritance and redefinition identities; it does not evaluate constraint consistency, OCL derivations or executable behavior.

Browse interactive properties · Concept-page contract