MagicDraw 19.0 LTR SP1 Documentation

Use the implied relation operation type if you need to specify indirect relations between the elements when going through a definable hierarchy. Implied relation operation collects indirectly associated elements according to the specified SourceCriteria and Target parameters.


SysML Block Definition Diagram

The figure above displays composition and inheritance structure between blocks. If a composite block depends on a particular element, the whole block also depends on this element. The same situation exists with inheritance between blocks. Inherited elements indirectly depend on the elements to which the parent element has relations. These indirect relations are referred to as implied relations, and can be displayed in a dependency matrix, as shown in the figure below.

A matrix showing implied relations

As shown in the figure, the High-voltage Battery block satisfies the Plug-in charge requirement. According to the composition and generalization, the Power SubSystem and High-voltage Battery Eco blocks should satisfy this requirement as well. In the matrix, these relationships are shown as implied, and marked with red, dashed arrows.

Implied relations can be created in:

  • Matrices
  • Relation maps
  • Tables
  • Derived properties
  • Smart packages


To specify an Implied Relation operation as a criterion

  1. Open the dialog for specifying criteria.
  2. In the criteria list on the left side of the dialog, select the Implied Relation operation. The Implied Relation criteria specification panel opens.

    Selecting Implied Relation operation

  3. In the Criteria drop-down list, select the desired relation.

    Specifying implied relation criteria

  4. In the Direction drop-down list, select the direction of the implied relation:
    • The Source To Target direction means that only the outgoing relations, which are pointing from the source element to the target element, are treated as the result of this criterion.
    • The Target To Source direction means that only the incoming relations, which are pointing from the target element to the source element, are treated as the result of this criterion.
    • If the Both direction is chosen, both cases described above are treated as a valid result.

      A source is a Contextual element, and a target is the result of the calculation.

  5. If you want direct relations to be displayed together with (and the same way as) implied relations, select the Include Direct Relations check box. However, be aware that after selecting this check box, there is no way to visually distinguish direct relations from implied relations.
  6. If the implied relation is created in a matrix or relation map, optionally modify the style of the relation by clicking  next to the Style box to open the Style dialog, then select preferred style properties and click OK.

  7. Click OK.

Criteria can be other relations than those listed in the Criteria drop-down list. In the Expert mode, any operation or even a combination of operations can be set as a criterion, e.g., metachain or find operation. In the Standard mode, an implied relation operation goes through a predefined hierarchy (a composition and generalization) to collect indirectly associated elements, whereas in the Expert mode, you can define your own hierarchy.

Manipulations in the Expert mode

The Expert mode allows you to change the CriteriaSource, and Target parameters of an implied relation operation. Specifying the Source and Target parameters lets you define your own hierarchy. You also have more flexibility in setting criteria with the ability to choose from a larger scope of operations, or even combine a few of them.

Implied relation operation goes through the Source parameter value to recursively collect elements, and uses the Criteria parameter value to navigate from the Source parameter results to implied elements. In addition, the Target parameter value recursively collects implied elements starting from the results of the Criteria parameter. The results of this operation are the results of the Criteria and Target parameters.

The parameters that can be specified in the Expert mode:

  • Source: specifies the operation that recursively collects elements starting from the Contextual element.

    The example shows the source of implied relation.

    In the example above, the value of the Source parameter is a generalization (direction – Source To Target). This means that starting from the High-voltage Battery Eco block, all generic classifiers are collected. In this case, the High-voltage Battery block is the result of the Source parameter. By default, the values of the Source parameter are simple navigation operations: a generalization (direction – Source To Target) and part (direction - Source To Target). Essentially, when a generalization is selected as the value of the Source parameter (direction - Source To Target), all general classifiers are recursively collected. And, when the value of the Source parameter is a part (direction - Source To Target), all composed part types (blocks) are recursively collected.

  • Criteria: specifies the operation that navigates to the elements from the results of the Source parameter. In other words, the value of the Criteria parameter is the relation for which implied elements are calculated. In the example above, the value of the Criteria parameter is a satisfy (direction – Source To Target). It means that starting from the result of the Source parameter - the High-voltage Battery block, the operation navigates through satisfy relation to collect implied elements. In this case, an implied element is the Plug-In charge requirement. Note that, by default, the direction of the criteria is Source To Target, and that sub-types are also included.

  • Target: specifies the operation that recursively collects elements starting from the result of the Criteria parameter. 

    The example shows the target of implied relation.
    In the example above, the value of the Target parameter is a generalization (direction – Target To Source). This means that starting from the AC Unit block, all composed blocks are collected. In this case, the Cooler block is the result of the Target parameter. By default, the values of the Target parameter are simple navigation operations - a generalization (direction - Target To Source) and part (direction - Target To Source).

To specify implied relation parameters in the Expert mode

  1. Once you select implied relation as a criterion, in the lower left corner of the dialog for specifying criteria, click Expert to enable the Expert mode.
  2. In the criteria list on the left side of the dialog, expand the implied relation operation, and select the parameter you want to specify.
  3. In the open pane for specifying the parameter, select the value you want to use.

    The image illustrates how to specify the criteria of an implied relation in the Expert mode.

  4. When you finish specifying required parameters, click OK.

    To set the value of the selected parameter as null, click the Reset button.

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