All functions - except the ones representing a process interface - must have exactly one connection to a service type or organizational unit. Functions must have only the following relationships in a model or function allocation diagram:
Exactly one Service type (OT_FUNC_CLUSTER) must be linked to a function via a connection of the supports (CT_CAN_SUPP_1) type.
Exactly one Position (ST_POS) must be linked to a function via a connection of the carries out type.
Exactly one Role (ST_EMPL_TYPE) must be linked to a function via a connection of the carries out (CT_EXEC_2) type.
Exactly one Organizational unit (ST_ORG_UNIT_1 and ST_ORG_UNIT_2) must be linked to a function via a connection of the carries out (CT_EXEC_1) type.
Exactly one Organizational unit type (ST_ORG_UNIT_TYPE_1 and ST_ORG_UNIT_TYPE_2) must be linked to a function via a connection of the carries out (CT_EXEC_1) type.
Exactly one Group (ST_GRP) must be linked to a function via a connection of the carries out type.
If no service type or organizational element is modeled, an error message occurs when a semantic check is performed for the model. If more than one service type or organizational element is modeled, an error message occurs and the model can no longer be transformed.