The realization relationship indicates that more abstract entities (“what” or “logical”) are realized by means of more tangible entities (“how” or “physical”). The realization relationship is used to model run-time realization; for example, that a business process realizes a business service, and that a data object realizes a business object, an artifact realizes an application component, or a core element realizes a motivation element.
The usual interpretation of a realization relationship is that the whole or part of the source element realizes the whole of the target element. This means that if, for example, two internal behavior elements have a realization relationship to the same service, either of them can realize the complete service. If both internal behavior elements are needed to realize, the grouping element or a junction can be used. For weaker types of contribution to the realization of an element, the influence relationship should be used.