Scot,
I think you meant to say that the "Alert Group" class is a subclass of cmdb_ci_service. The Alert Group class is also a subclass of Application Service. It is rarely used but like other Applications services, it is visualized using a Service Map.
The Service Classification field was used by legacy SPM "Services" that were used as place holders until they could be migrated to a specific ITOM service class. With the definition of Application Services in the CSDM, SPM services should only be used to represent Catalog Services and offerings. ITOM Services all have their own classifications (unique class names) so the Service Classification field should not be assigned to CIs in the ITOM Service classes.
Another clarification: The Service Group and Application Service Classes and their subclasses are all operational ITOM services that make up the operational service hierarchy. The service hierarchy is used by event management to propagate monitoring alerts from low level application and hardware CIs upward to the highest level Service Groups that represent Enterprise Services and the environments (Prod,QA,test,Dev) they run on. Service groups are also included in the Impacted CIs list when making changes. Enterprise level Services that are represented by Service Groups frequently hold CAB reviews to see what upcoming changes could impact them. Prior to the CSDM and Service Mapping, the use case for Services Groups was not well defined, so customers used other classes (like Application) to model them.
The business_service field on ITSM forms has always been intended to be used with ITOM services (Application Services used to be called Business Servces). ITOM services (ITOM Services Groups and Application Services) should appear on ITSM forms so incidents and changes get associated with them. That way if they alert on the dashboards, you can see the most recent changes and incidents that may be related to the Alert. ITOM services appear on the Event Dashboard and Operator workspaces because they can have a severity that is dynamically calculated based on the severity of their subcomponents.
SPM "services" (Business Services, Technical Services, and Service Offerings) are not operational so they won't have a severity and are not monitored. In my opinion, they should never have been moved into the Service class hierarchy because they are not services (they are all Service Catalog offerings).
