The CMDB is a set of one or more connected databases and information sources that provide a logical model of the IT infrastructure. It captures Configuration Items (CIs) and the relationships that exist between them.
It is important to determine what level to which the CMDB will record information about the IT infrastructure and to decide what is not covered within the scope of the CMDB. Components out of scope are those typically not under the control of Change Management (e.g. telecommunication equipment). The CMS is also used for a wide range of purposes, including business processes where information is required for financial, compliance, HR or other reasons.
At the data level, the CMS may be formed by a combination of physical Configuration Management Databases (CMDBs), as well as other sources they feed and interface information together. Wherever possible, the CMS should provide access to information for other inventories rather than duplicating the data captured. Automation is a factor for success for larger CMS deployments, with discovery, inventory, audit, network management and other tools being used with interfaces to the CMS.