The Service viewpoint is based on the concept of a Service-Oriented Architecture (SOA), which is fundamental to the NNEC paradigm. It is a description of services needed to directly support the operational domain as described in the Logical viewpoint. A service, within the Service viewpoint, is understood in its broadest sense, as a unit of work through which a provider provides a useful result to a consumer. It focuses strictly on identifying and describing services. The viewpoint also supports the description of service taxonomies, service orchestrations, a mapping of services to operational activities, and a description of various forms of service behavior.