Allocations and other Relationships

A fundamental aspect or discipline in Systems Engineering is to relate structural elements with behavioral elements. These two important aspects of a model will become intertwined as a model develops, but when a number of engineers start work to define the system it is often difficult to say exactly how the behavior and the structure will be related. The Allocation relationship is particularly useful in these situations. It can be used as a way of showing the relationship between behavioral elements and structural elements that will inform the more rigorous modeling that will be employed as the notions described in the model become more certain.

Enterprise Architect also supports a number of other ways of representing the Allocation relationship, including as a compartment in either the behavior or structure element.

Any element that allows compartments can be configured to hide or show any number of available compartments. The list of compartments is specific to an element and is dynamic, meaning that a compartment will only be visible if the element participates in one or more relationships of the specified type and the relationship is not visible on the containing diagram. The same options can be used to display a range of other structural or semantic aspects of the elements as shown here.

It is also possible to show the relationship in a callout notation, where a note is connected to the element and displays the name of the relationship and the details of the related element. This diagram shows the notation for an Activity, showing the Block that it has been allocated to. To achieve this an engineer must:

1. Ensure the relationship is displayed in the diagram.
2. Select the relationship and display the context menu.
3. Choose the 'Create Linked Note' option.

This callout notation can be used with any type of SysML element or relationship, and is a useful way of displaying the relationship for some types of audiences.