Common Data Model component of BMC Atrium CMDB
You have many different types of configuration items (CIs), from computer systems to network hardware to software servers. Without a data model that accurately reflects these types and the types of relationships that can exist between them, your CMDB could store attributes that do not pertain to their CIs, leave out necessary attributes, and make it harder to search for groups of CIs.
The BMC Atrium Configuration Management Database (BMC Atrium CMDB) data model is object oriented, which means that it has a hierarchical set of classes in which each class inherits attributes from its superclass (the class above it in the hierarchy) and then adds its own attributes to create a more specific type of object, a subclass. The benefits of an object-oriented data model include enforcement of common attributes among similar types of CIs and the ability to search within not just a given class of CIs, but within any branch of the hierarchy. From a base class from which all others are derived, you can search for all CIs or all relationships.
The BMC Atrium CMDB data model is also extensible. Your infrastructure, and the technology that comprises it, is constantly changing. That means the types of CIs and relationships in your CMDB must also change, so you need a data model that is extensible. You can add attributes to your classes, and even add classes. Subclasses can have their own subclasses, extending the hierarchy to the level of detail that you want to track.
The Common Data Model (CDM) is the set of CI and relationship classes that ships with BMC Atrium CMDB. These classes are complete enough to model nearly everything in your IT environments. All classes in the CDM reside in the BMC.CORE namespace.
For consistency with industry standards developed to track and manage this type of information, the CDM is based on the Common Information Model (CIM) from the Distributed Management Task Force (DMTF) and Microsoft Windows Management Instrumentation (WMI). The CDM adopted much of the basic design of the CIM and WMI without detailing the internal workings of systems. For a graphic of the CDM, see the BMC Atrium CMDB 8.1.00 Common Data Model Diagram.
Recommendations for modeling your environment in the CDM are available in Modeling business entities.