OV-7 Template
Product Definition. The Logical Data Model describes the structure of an architecture domain’s system data types and the structural business process rules (defined in the architecture’s Operational View) that govern the system data. It provides a definition of architecture domain data types, their attributes or characteristics, and their interrelationships. Product Purpose. OV-7 including the domain’s system data types or entity definitions, is a key element in supporting interoperability between architectures, since these definitions may be used by other organizations to determine system data compatibility. Often, different organizations may use the same entity name to mean very different kinds of system data with different internal structure. This situation will pose significant interoperability risks, as the system data models may appear to be compatible, each having a Target Track data entity but having different and incompatible interpretations of what Target Track means. An OV-7 may be necessary for interoperability when shared system data syntax and semantics form the basis for greater degrees of information systems interoperability, or when a shared database is the basis for integration and interoperability among business processes and, at a lower level, among systems.
Product Detailed Description. OV-7 defines the architecture domain’s system data types (or entities) and the relationships among the system data types. For example, if the domain is missile defense, some possible system data types may be trajectory and target with a relationship that associates a target with a certain trajectory. On the other hand, architecture data types for the DoDAF (i.e., DoDAF-defined architecture data elements, AV-2 data types, and CADM entities) are things like an operational node or operational activity. OV-7 defines each kind of system data type associated with the architecture domain, mission, or business as its own entity, with its associated attributes and relationships. These entity definitions correlate to OV-3 information elements and OV-5 inputs, outputs, and controls.
Although they are both called data models, OV-7 should not be confused with the CADM. OV-7 is an architecture product and describes information about a specific architecture domain. The CADM is not an architecture product. The CADM is a database design for a repository of DoDAF products and architecture data. CADM-based repositories can store architecture products, including Logical Data Models, from any DoDAF-based architecture project. Thus, the CADM addresses a structure for storing architecture data (e.g., instances of operational nodes and operational activities), while a Lo gical Data Model for missile defense, for example, might define architecture domain entities and relationships such as missile tracks and points of impact.
The purpose of a given architecture helps to determine the level of detail needed in this product. A formal data model (e.g., the Integrated Definition for Data Modeling [IDEF1X]) [FIPS 184, 1993] that is detailed down to the level of architecture domain system data, their attributes, and their relationships is required for some purposes, such as when validation of completeness and consistency is required for shared data resources. However, for other purposes, a higher- level conceptual data model of the domain of interest will suffice, such as a subject area model or an entity-relation model without attributes. The term logical data model is used here in this context, regardless of the level of detail the model exhibits.
The architecture data elements for OV-7 include descriptions of entity, attribute, and relationship types. Attributes can be associated with entities and with relationships, depending on the purposes of the architecture.