We observe that Figure 1 contains conceptually arbitrary services. The author (a person) is directly connected to services ―Submit article,‖ ―View submitted articles,‖ and ―Edit author data.‖ The connection seems to mean that these three services are available to authors. Nevertheless, ―availability‖ is not a notion that should guide the classification of services at this level. The modeling should be guided by a conceptual hierarchy of relationships of services. ―Submit article‖ and ―View submitted articles‖ are article-related services, while ―Edit author data‖ is related to a different artifact (to be explained later).