Structurally relevant objects
Structurally relevant objects are basic model objects that that define the distinctive feature of a model. For a model of the Organizational chart type, the objects Organizational unit, Role, and Person are structurally relevant objects, for example. Using these items, you can build the typical hierarchy of an organizational chart.
The Event and Function objects are typical for the EPC model type and are thus structurally relevant to a business process. You can use these to establish a typical control flow. The Organizational unit, Role, and Person objects can also be inserted into an EPC. However, these objects do not constitute the distinctive feature of a business process. As structurally irrelevant objects in an EPC, they act as satellites and add more detailed information to the process model. For example, you can insert organizational units and link them to functions to illustrate who carries out those functions.
An object that can be inserted into a model or diagram but is not a structurally relevant object is a satellite.