RequirementsLink represents a relation between two or more Requirements. Source and target Requirements of the relation are distinguished, which means that the relation is directed (from source to target). If such a distinction does not make sense, then use a RequirementsRelationGroup instead.<br/><br/>The standard case will be a relation with one source and one target Requirement. However, it is possible to have several source and/or several target Requirements so that general relations can be expressed with instances of this metaclass.<br/><br/>The semantic of a concrete Requirement relation can be provided by the modeler. In particular, three ways are conceivable:<br/><br/>(1) The user attributes of the relation can be used to specify its meaning, for example with a user attribute called "relationType" which is set to values such as "needs" or "excludes".<br/><br/>(2) The UserAttributeElementType can be used. Certain types will be used for certain relation semantics.<br/><br/>(3) RequirementsRelationGroups can be used, i.e. all relations with an "excludes" meaning are put in one relation group and all with a "needs" meaning are put in another.<br/><br/>Semantics:<br/>The RequirementsLink defines a relation from a set of source and target requirements. The isBidirectional attribute defines whether the relation is bidirectional. The semantics of the relation is user-defined.<br/>
When set to true, the semantic relation represented by this instance of RequirementRelation does not only apply to the direction from source to target (as always) but also in the opposite direction.<br/><br/>Note that this means that the relation becomes directed in both directions but NOT undirected. To express an undirected association use a RequirementsRelationGroup.<br/>
