 between two business enti- ties is called a relationship. It should be noted that a business entity can estab- lish an association with itself. 5. Domain: These are a collection of ABEs associated with a specific management area that are derived from analysis of process and information frameworks. It can be seen that domains making up the SID framework are consistent with eTOM level 0 concepts. The SID framework comprises of business entities and their attributes represented using UML models with process mapping to eTOM. The SID specifications are grouped into domains, each of which has a set of SID business entities and attri- butes collected in aggregate business entities that can be directly used for data design by the service developers and service providers. There is coupling between the different SID domains with a high degree of cohesion within the domain (see Figure 24.1). Use of SID leads to business benefits relating to cost, quality, timeliness, and adaptability of enterprise operations. With standard information and interface models, service providers can focus on value creation for their customers without worrying about the interoperability between applications. The most compelling requirement in enterprises of achieving business and IT alignment can be achieved with the SID model apart from satisfying the NGOSS information and data needs. SID derives its roots from the eTOM that provides a business process reference framework and common business process vocabulary for the communications industry. The eTOM offers enterprises an effective way to organize their business processes and the communication between these pro- cesses. The companion model to the eTOM, the SID business view model provides an information reference model and a common vocabulary from a business entity perspective. The SID uses the concepts of domains and aggregate business entities (or subdo- mains) to categorize business entities, thereby reducing duplication and promoting reuse. The SID scheme is categorized into a set of layer