About relationship types
This topic describes how to use relationship types to describe or identify the relationships in your project.
In this topic
What are relationship types?
When you create relationships between items in your project, you need to indicate the nature of those relationships by selecting a relationship type. Relationship types classify the relationships within your project and allow you to make comparisons between all the relationships of a particular type.
You can use the system-created 'Associated' relationship type or you can create your own relationship types—for example, knows, employs, reduces, impacts and so on.
Relationship types have both a name and a direction. It is a good idea to name relationship types with a verb or verbal expression—for example, employs or works with. Verbal relationship type names assist because they make it clear what is being stated, clarify the relationship type's direction and what items the relationship is from and to.
When you add a relationship type, you can define one of the following directions:
-
Associative (Anna 'knows' Ken)
-
One way (Anna 'employs' Ken)
-
Symmetrical (Anna 'works with' Ken)
Understanding the direction of a relationship type
When you create a relationship type, you must give it a direction. There are three possible directions, each giving different meanings to the relationships you create:
-
Associative An associative relationship can be used to demonstrate that items are in some way affiliated. Associative relationships between two items must always hold both ways—for example, Anna 'knows' Ken, Ken must also know Anna.
-
One-way A one-way relationship can be used to demonstrate a relationship between items which has a definite direction, an agent and a recipient—for example, industrial waste 'degrades' water quality.
-
Symmetrical A symmetrical relationship demonstrates a two-way activity between the items. These relationships imply they hold both ways, such as 'being married to' or 'being a sibling of'.