A key concept of ITIL is a configuration management system consisting of one or more configuration management databases (CMDBs), other management data repositories, and processes to maintain the fidelity of the data. The data consists of configuration items (CIs) and relationships between CIs and with process artifacts, such as incidents, problems, changes, and releases. A properly constructed CMDB is a knowledge base for service management processes. This presentation describes the core features of an effective configuration management system. Topics covered include linking configuration and (financial) asset information; integrating trusted data sources; building on a rich and extendible data model; cleansing and reconciling data; federating multiple repositories; auditing to maintain data accuracy; controlling user access to specific data; and leveraging and customizing the model as a foundation for service management processes.