Figure 9-15: Usage example of item flows in internal block diagrams

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

Tags and keywords

Slide kind

hybrid diagram

SysML Block Definition Diagram (BDD)

SysML Internal Block Diagram (IBD)

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Some additional elements beyond the spec diagram have been included here, such as the Blocks Radiator, Water Heater, and Water Distiller in the BDD, before they are connected up in the IBD. The usual Webel Best Practice is:

SysMLv1: Prefer not show Port symbols on the boundary of Block symbols in BDDs, just list them in compartments. One can't connect them in a BDD anyway. Recommend only show Port symbols in IBDs.

But the Port symbols have been shown in the BDD just to show how one can expose the underlying flow properties of the Ports' types by enabling the so-called "Part Compartments":

The MagicDraw/Cameo feature "Enable Parts Compartments" really means "Enable SysML Compartments"

These can also be shown in the IBD, but then one loses the flow direction indicators on the Ports (which is not so bad if the ItemFlow direction is clear anyway).

Up next

Figure 9-16: Usage example of item flow decomposition

Notes

[CAPABILITY, FEATURE, TOOL] MagicDraw/Cameo: Supports embedding of one or more Diagrams in another via the Diagram Overview feature. Awesome!

[MODELLING, STYLE]{RECOMMENDED} SysMLv1: Prefer not show Port symbols on the boundary of Block symbols in BDDs, just list them in compartments. One can't connect them in a BDD anyway. Recommend only show Port symbols in IBDs.

[CAPABILITY, DISPLAY, TOOL] The MagicDraw/Cameo feature "Enable Parts Compartments" really means "Enable SysML Compartments"

[CAPABILITY, FEATURE, STYLE, TIP] TIP: MagicDraw/Cameo: Consider showing the Port name and type label inside the Port symbol! CAVEAT: This loses the direction indicators on Ports typed by Blocks with flow properties (but is fine if ItemFlows show the direction, or for "contract ports").

Snippets (quotes/extracts)

[SysML-1.6] Item flows in internal block diagrams specify flows local to a block.

[SysML-1.6] The water heater is fed from a water distiller in this particular usage, so the modeler knows the output will always be distilled water, rather than other kinds of water.

[SysML-1.6] The radiator on the left requires distilled water, and its connection to the water heater is compatible because the item flow narrows the items to distilled water.

[SysML-1.6] Item flows can also be more general than the actual flow, as shown by the connector on the right. The water distiller produces distilled water, but the item flow is for any kind of fluid.