UML provided/required Interfaces vs SysML DirectedFeatures on Ports

Gallery
Tutorial
TRAIL: Webel's ultimate guide to Systems Modeling Language (v1) with MagicDraw/Cameo
Section
09:04: Ports and contracts
UML keywords
provided Interface
required Interface
SysML keywords
nested Port
DirectedFeature
FeatureDirectionKind::provided
FeatureDirectionKind::required
Slide kind
hybrid diagram
SysML Block Definition Diagram (BDD)
SysML Internal Block Diagram (IBD)
Let's see the UML provided/required Interface side-by-side against the SysML DirectedFeature approach:
Click on the image to view it full size

In the BDD the UML Interface operations can be read, but not in the IBD. SysMLv1 DirectedFeatures can be shown in IBDs:

SysML-1.7: 'SysML permits any property shown on an internal block diagram to also show compartments within the property box. These compartments may be given standard or user-customized labels just as on block definitions.'

And how about that, you can use the SysML DirectedFeature compartments on nested ports too! So you can, for example, use an outer Port for a physical contract and an inner Port for a logical contract (such as a channel) and expose the contract easily.

Webel Best Practice: 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!
Up next
09:05: FlowProperty and Ports with flows
Notes
[CAPABILITY, FEATURE, TOOL] MagicDraw/Cameo: Supports embedding of one or more Diagrams in another via the Diagram Overview feature. Awesome!
[ASSERTION, WISHLIST] SysMLv1.6 Provided/required DirectedFeature contracts for ProxyPorts SHOULD be satisfiable Feature-wise (including as subsets of Features) not necessarily just at the level of entire Blocks (types)! [See also the SysMLv1.7 spec changes.]
[ISSUE, WARNING] In SysML the NOW DEPRECATED (since SysML-1.6) direct UML Port conjugation does not work consistently with SysML DirectedFeature and SysML FlowProperty on nested ports!
[TIP]{STRONG} 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!
Snippets (quotes/extracts)
  [SysML-1.7] 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).
  [SysML-1.7] 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 ...
  [SysML-1.7] 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
  [SysML-1.6] SysML permits any property shown on an internal block diagram to also show compartments within the property box. These compartments may be given standard or user-customized labels just as on block definitions.
  [SysML-1.6] [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 ...
Visit also
Visit also (backlinks)
Related slides (includes other tutorials)
Related slides (backlinks, includes other tutorials)
BehavioredClassifier and provided and required Interfaces
Required/Provided Interface notation: Ball-and-Socket "dependency wiring" [tool specific]