The term configuration item (CI) refers to the fundamental structural unit of a configuration management system. Examples of CIs include individual requirements documents, software, models, and plans. The configuration-management system oversees the life of the CIs through a combination of processes and tools by implementing and enabling the fundamental elements of identification, change management, status accounting, and audits. This system aims to avoid the introduction of errors related to lack of testing as well as of incompatibilities with other CIs.
CIs cannot be used in manufacturing sectors as it doesn't have any scope to include such configurations. Even though CIs are not mandatory in this domain but having a version management of Bill of Material is essential.
The term "configuration item" can be applied to anything designated for the application of the elements of configuration management and treated as a single entity in the configuration-management system.
A release (itself a versioned entity) may consist of several configuration items. The set of changes to each configuration item will appear in the release notes, and the notes may contain specific headings for each configuration item. A complex hardware configuration item may have many levels of configuration items beneath its top level; each configuration item level must meet the same fundamental elements of the configuration management system.
In addition to its purpose in the implementation and management of a change, each configuration item's listing and definition should act as a common vocabulary across all groups connected to the product. One should define the CI at a level such that an individual involved with product marketing and an individual responsible for implementation can agree to a common definition when they use the name of the configuration item. Selection and identification of configuration items for a particular project can be seen as the first step in developing an overall architecture of the product from the top down.
Configuration items, their versions, and their changes form the basis of any configuration audit.
CI types are: