Type of Relation (Components)
The following relation types can exist between the components of
		a business object.
- one-to-one - A component must have a relation with only one other
		component. 
- zero-to-one - A component can have a relation with only one other
		component. 
- one-to-many - A component must have a relation with one or more other
		components. 
- zero-to-many - A component can have a relation with one or more other
		components.