Features that are not denoted as a DirectedFeature are implicitly provided features. As such they can be matched against a corresponding required feature. Source OMG Systems Modeling Language (SysML) 1.7beta1
Conjugation in SysML-1.7 is Type-based: InterfaceBlock, ~InterfaceBlock, and DirectedFeature Gallery Tutorial TRAIL: Webel's ultimate guide to Systems Modeling Language (v1) with MagicDraw/Cameo Section 09:03: Port conjugation in SysML is now Type-based Slide kind SysML Block Definition Diagram (BDD)
A providedRequired feature specifies a symmetric dependency between two connected blocks whereby a block’s internal use of such a feature is delegated to the connected block with the corresponding feature and conversely that block’s internal use of ... Source OMG Systems Modeling Language (SysML) 1.7beta1
A DirectedFeature indicates whether the feature is supported by the owning block (provided) for other connected blocks to use, or is to be supported by a connected block for the owning block to use (required), or both (providedRequired). Source OMG Systems Modeling Language (SysML) 1.7beta1
Webel: SysML1.7: Port contract matching is Feature-based, not Type-based. There's nothing particularly magical or special about use of an ~InterfaceBlock on a "conjugating" SysML Port, it's just a convenient way of managing one-to-one Feature matching!
For example, a block might provide particular services to other blocks as operations, or have a particular geometry accessible to other block, or it might require services and geometries of other blocks. Source OMG Systems Modeling Language (SysML) 1.6
Required and provided features are operations, receptions, and non-flow properties that a block supports for other blocks to use, or requires other blocks to support for its own use, or both. Source OMG Systems Modeling Language (SysML) 1.6
Directed features can appear in compartments for the various kinds of properties and behavioral features. Source OMG Systems Modeling Language (SysML) 1.6
A DirectedFeature has the same notation as other non-flow properties and behavioral features with a feature direction prefix (prov | reqd | provreqd), which corresponds to one the FeatureDirectionKind literals “provided,” “required,” and “providedrequired Source OMG Systems Modeling Language (SysML) 1.7beta1
[SysML1.6: PREFER SysML1.7] A DirectedFeature indicates whether the feature is supported by the owning block (provided), or is to be supported by other blocks for the owning block to use (required), or both ... Source OMG Systems Modeling Language (SysML) 1.6
Conjugation is specified by a constraint giving the features of ~InterfaceBlocks according to those of their original InterfaceBlocks ... It is expected that tools conforming to this specification automatically create features of ~InterfaceBlocks. Source OMG Systems Modeling Language (SysML) 1.6
InterfaceBlock ... for example, in flow properties are conjugated as out flow properties and provided features are conjugated as required features. Source OMG Systems Modeling Language (SysML) 1.6
In general, the SysML DirectedFeature approach is more powerful and the notation is cleaner than UML provided/required Interfaces. Prefer SysML DirectedFeatures unless you have a really good reason to use Interfaces!
Provided/required Interface "lollipop" and "socket" (a.k.a. ball-and-socket) notation can quickly lead to clutter in UML Composite Structure Diagrams and SysML Internal Block Diagrams. SysML provided/required DirectedFeature notation is cleaner.
Figure 9-6: Usage example of ports with provided and required features Gallery Tutorial TRAIL: The SysML-1.6 Hybrid SUV sample and specification diagrams in MagicDraw/Cameo (with annotations) [UNDERGOING UPDATE to SysML1.7] Section Section: SysML-1.6 specification diagrams: 09 Ports and Flows Slide kind SysML Internal Block Diagram (IBD)
Figure 9-4: Provided and Required Features Gallery Tutorial TRAIL: The SysML-1.6 Hybrid SUV sample and specification diagrams in MagicDraw/Cameo (with annotations) [UNDERGOING UPDATE to SysML1.7] Section Section: SysML-1.6 specification diagrams: 09 Ports and Flows Slide kind UML Profile Diagram
