The current version of my Service Excellence Model can now be found as a fixed page on this blog. (In the right-hand nav on a desktop browser).
The model provides an overview of all the optional and mandatory components I believe are involved in delivering an excellent service.
This is designed to be complete and comprehensive and therefore should be used as a guide and not a rule-set. Depending on the specific details of a given service or situation the different components may require different emphasis. Some components may become compulsory in some circumstances, but not required or at least much less significant in other circumstances. This is something only the service provider can decide.
However, regardless of the situation I think all components should at least be consciously considered when designing, delivering or changing a service.
As the often used online TLA goes - YMMV.