Functional allocation of an Activity (definition level) in a BDD with callouts

Before looking at making functional allocations in an Activity Diagram, we start with some of the kinds of allocations one can make directly in a BDD using the Allocate relationship, noting that in SysML one can show Activities directly in BDDs as rectangles with the keyword «activity» applied.

Not all of these kinds of possible (allowed) allocations shown here are recommended!

This diagram here happens to show the computed 'allocatedFrom' and 'allocatedTo' information using "callouts" into Notes, but one can also show this information on symbol compartments:

Click on the image to view it full size

The allocation from the Activity AllocateMeToBlock to Block DoesIt is at pure definition level, and is one recommended higher level form of functional (behavioral) allocation.

The "mixed" allocation from the Activity AllocateMeToPart (at definition level) to part Property part:Inner (at usage level) is definitely NOT recommend here:

Webel Best Practice: AVOID "mixed" functional (behavioral) allocation levels! DO NOT Allocate from Usage level (Action) to Definition level (Block) or from Definition level (Activity) to usage level (part Property) - even if formally permitted in SysML.

Some useful tool tips:

MagicDraw/Cameo: The Allocate relationship is available in all SysML diagram types under the Common sidebar menu group (but you can only use it to make allocations between elements that both appear in a given diagram).

MagicDraw/Cameo: The Allocate relationship is available on many element kinds on most SysML diagram types as a smart manipulator (click symbol once then look at right of symbol).

Blocks are ultimately used in a context as part Properties (or other kinds of block Properties), and Activities are used in a context as Actions (typically via CallBehaviorActions), as we examine next .

Up next

Functional allocation of a CallBehaviorAction (usage level) in an Activity Diagram to elements in a BDD

Notes

[POLICY, WARNING]{STRICT} AVOID "mixed" functional (behavioral) allocation levels! DO NOT Allocate from Usage level (Action) to Definition level (Block) or from Definition level (Activity) to usage level (part Property) - even if formally permitted in SysML.

[ISSUE, TOOL] MagicDraw/Cameo 19SP3: The property path in callout does always correspond to the SysML spec examples.

[FEATURE, TIP, TOOL] MagicDraw/Cameo: The Allocate relationship is available in all SysML diagram types under the Common sidebar menu group (but you can only use it to make allocations between elements that both appear in a given diagram).

[FEATURE, TIP, TOOL] MagicDraw/Cameo: The Allocate relationship is available on many element kinds on most SysML diagram types as a smart manipulator (click symbol once then look at right of symbol).

Snippets (quotes/extracts)

[SysML-1.6] Activities in block definition diagrams appear as regular blocks, except the «activity» keyword may be used to indicate the Block stereotype is applied to an activity, as shown in Figure 11-1. See example in 11.4, Usage Examples.

[SysML-1.6] Allocate is a dependency based on UML::Abstraction. It is a mechanism for associating elements of different types, or in different hierarchies, at an abstract level. Allocate is used for assessing user model consistency and directing future design ...

[SysML-1.6] It is expected that an «allocate» relationship between model elements is a precursor to a more concrete relationship between the elements, their properties, operations, attributes, or sub-classes.

[SysML-1.6] Allocate is a stereotype of a UML4SysML::Abstraction that is permissible between any two NamedElements. It is depicted as a dependency with the "allocate" keyword attached to it.