Increasingly companies wanting to develop an Enterprise Architecture are also looking at a Service Oriented Architecture approach.
Consequentially one of the deliverables that needs to be defined in the Enterprise Architecture Framework is a Service Catalogue.
In fact there are two kinds of Service Catalogue that often get confused in casual conversation, an Application Service Catalogue and an Organisation Service Catalogue (or Business Service Catalogue).
Application Service Catalogue:
This is located in the Application Architecture column of the EA Framework and defines the Application Services (i.e. those Services that are performed by software applications, implemented as web services, and typically invoked in composite applications using a Process Orchestration).
These Application Services form part of a Service Oriented Architecture approach to building composite service based applications.
Generally I identify the Service Oriented Architecture as the main part of the target architecture vision.
Organisational Service Catalogue:
This is located in the Organisation Architecture column and defined those services that are provided by people or organisation units.
Often these are called 'Business Service Catalogues'.
Organisations typically identify these Organisation Services as a result of decomposing their Functions into Business Units and then considering what those Business Units do.
If the Organisation Services are well defined, regarded as non-core commodity services, then they can often be outsourced.
In summary, Application Services belong to the Service Oriented Architecture and Organisation Services belong to a Service Based Business approach.
Of course a high level composite Service can include both an Organisation Service and a set of Application Services...