Simplification and preserving consistency
How can I simplify my views without compromising the consistency?
Within ArchiMate it is possible to deduce indirect relationships by compositions of relationships. This is described in paragraph 5.7 of the book EA at work. This is considered an indispensable instrument for visualizing architecture: leave out some details and at the same time maintain consistency between models.
For structural relationships, a powerful composition rule has been developed based on the strength of the relationship. In a chain of concepts the most ‘weak’ relationship in the chain determines the overall relationship between the endpoint concepts of the chain. The table below shows the strength of structural relationships. Figure 5-37 shows an example of this composite rule.
In this example, the indirect relationship between the process Registration and the application function Manage Customer data is a used by relationship because this has a lower weight than a realization.
Relationship Strength association 1 access 2 used by 3 realization 4 assignment 5 aggregation 6 composition 7
- Table: Strength of structural relationships
- Figure 5 37: Example of an indirect relationship – used by
The following rules apply for the two dynamic relationships:
- A triggering or flow relationship between behavioral elements (for example processes or functions) may be redirected to structural elements (for example business actors or application components) to which they are assigned.
- Figure 5 38: Example of an indirect relationship - flow
- A triggering- or flow relationship between behavioral elements may be redirected to the services that they realize.
- Figure 5 39: Example of an indirect relationship - trigger
Views can be simplified in this manner to a level of detail that is relevant for the goal of the view, without losing consistency. Not every tool supports this simplification. The consequences are that redundant relationships may exist. In the above example of the services this implies that the existing relationship between the processes is registered in the tool (left part). If the relationship between the services is visualized in another view (right part), the tool may introduce an extra triggering relationship between these services.
Relationships with other good practices
These simplifications can be applied to any good practice.