One of the important aspects of SOA Governance that we have been discussion is that of Service Domains: rather than having a lines of business own systems, Service Domain Owners choose Service Domains which group a set of related services. These affinity of these services are often of a business nature, or originating from a buisness perspective at the very least.
Decomposing a business domain into its sub-domains and functional areas enables a set of natural boundaries that can be a good starting point for Service Domains.
The Service-oriented Modeling Approach uses this strategy to identify domains, decompose them and then put governance around them.
Every domain owner will provide a set of services and wil in turn, itself require a set of services for consumption.
Thus the publication of the servcie descriptions of both these sets of services are critical to get the service eco-system going in your enterprise.
This allows the Domain Owners to make decisions about implementation changes to Service Implementations without changing the Servcie Description, if the change does not affect the SLA (service level agreement) and QoS (quality of service).
A set of base services can be instilled into an organization as the primary business functions it provides and decide which ones it in turn requires from its business partners. (the DNA approach we discussed earlier , recognizing the fact that there are three approaches to this paradigm, each of which may fit your enterprise.
Instill, let go and observe the evolution of services as they are adopted at various levels of maturity (or not), exercise governance for communication of the services, obtaining feedback to ensure they are relevant and to check for compliance.