HP WBEM Services Software Developer's Kit for HP-UX Provider and Client Developer's Guide A.01

Schema Design and Implementation
Schema Design
Chapter 3 35
STEP 3: Consult DMTF Model
DMTF has developed a general-purpose, implementation-independent
schema for use in a large variety of applications, such as general
computer systems, network devices, embedded systems, and storage
arrays. The CIM schema is divided into several major categories:
• Core: base classes from which all other schemas are derived
• System: high-level representations of systems, with additional
details for computer systems
• Application: used to manage the lifecycle of software products,
drivers, firmware, and applications
• Device: logical representations of configuration and operation on
hardware devices
• Event: representation of indications and subscriptions
• Metrics: classes for units of work and associated metrics
• Network: representations of network cloud and associated services
• Physical: the descriptions of entities which can be labeled, occupy
space, and are subject to physical laws (that is physical vs. logical
entities in the Device schema)
• Policy: representation of rules and their dependencies
• Support: models of service incidents
• User: the CIM user and security models
Analysis of a schema for a specific domain can usually be confined to 2 to
4 of the above categories. For example, modeling a managed resource
such as a Network Interface Card (NIC) would encompass objects in the
physical (the card itself), the device (the logical representation), the
network (the protocol stack), and the application (the driver) schemas.
The basic task is to identify DMTF CIM classes intended to represent
similar information to that of draft classes for the domain. This exercise
may result in either dividing the draft classes (identified in Step 1 above)
into multiple DMTF-derived classes (extensions to the DMTF model)
with appropriate associations, or merging draft classes to correspond to a
defined DMTF class. Use of the classes from the DMTF schema
facilitates interoperability between clients and providers. Providers can