ITIL Configuration Management
Configuration Management is an integral part of all other Service Management processes. With current, accurate and comprehensive information about all components in the infrastructure the management of Change, in particular, is more effective and efficient. Change Management can be integrated with Configuration Management. As a minimum it is recommended that the logging and implementation of Changes be done under the control of a comprehensive Configuration Management system and that the impact assessment of Changes is done with the aid of the Configuration Management system. All Change requests should therefore be entered in the Configuration Management Database (CMDB) and the records updated as the Change request progresses through to implementation.
The Configuration Management system identifies relationships between an item that is to be changed and any other components of the infrastructure, thus allowing the owners of these components to be involved in the impact assessment process. Whenever a Change is made to the infrastructure, associated Configuration Management records should be updated in the CMDB. Where possible, this is best accomplished by use of integrated tools that update records automatically as Changes are made.
The CMDB should be made available to the entire Service Support group so that Incidents and Problems can be resolved more easily by understanding the possible cause of the failing component. The CMDB should also be used to link the Incident and Problem records to other appropriate records such as the failing Configuration Item (CI) and the User. Release Management will be difficult and error prone without the integration of the Configuration Management process.
The Service Delivery processes also rely on the CMDB data. For example:
- Service Level Management needs to identify components that combine together to deliver the service so that underpinning agreements can be set up
- Financial Management for IT needs to know the components utilised by each business unit especially when charging is in place
- IT Service Continuity and Availability Management need to identify components to perform risk analysis and component failure impact analysis.
Configuration Management - Service Asset and Configuration Management
Service Asset and Configuration Management (SACM) manages the service assets and Configuration Items (CIs) in order to support the other service management processes. SACM defines the service and infrastructure components and maintains accurate configuration records.
Basic concepts: A Configuration Item (CI) is an asset, service component or other item that is (or will be) controlled by configuration management.
An attribute is a piece of information about a CI. For example version number, name, location et cetera.
A relationship is a link between two CIs that identifies a dependency or connection between them. Relationships show how CIs work together to provide a service.
By maintaining relations between CIs a logical model of the services, assets and infrastructure is created. This provides valuable information for other processes.
A configuration structure shows the relations and hierarchy between CIs that comprise a configuration.
Configuration management ensures that all CIs are provided with a baseline and that they are maintained. A baseline can be used to restore the IT infrastructure to a known configuration if a change or release fails.
CIs are classified (the act of assigning a category to a CI) to help manage and trace them throughout their lifecycles, for instance: service, hardware, software, documentation, staff.
A Configuration Management Database (CMDB) is a database used to store configuration records of CIs. One or more CMDBs can be part of a Configuration Management System.
In order to manage large and complex IT services and infrastructures SACM needs to use a supporting system: the Configuration Management System (CMS).
Various libraries are defined:
- A secure library is a collection of software and electronic CIs (documents) of aknown type and status.
- A secure store is a secure location where IT assets are stored.
The Definitive Media Library (DML) is a secure store where the definitive, authorized (approved) versions of all media CIs are stored and monitored.
Definitive spares are spare components and assemblies that are maintained at the same level as the comparative systems within the live environment.
A snapshot ("moment in time") is the state of a configuration at a certain point in time (for instance when it was inventoried by a discovery tool). It can be recorded in the CMS to remain as a fixed historical record of the configuration, not necessarily authorized.
Activities The basic SACM process activities consist of:
- Management and planning - The management team and configuration management decide what level of configuration management is needed and how this level will be achieved. This is documented in a configuration management plan.
- Configuration identification - Configuration identification focuses on establishing a CI classification system. Configuration identification determines: the configuration structures and selection of CIs; the naming conventions of CIs, the CI labels; relations between CIs, the relevant attributes of CIs, type of CIs et cetera.
- Configuration control - Configuration control ensures that the CIs are adequately controlled. No CIs can be added, adapted, replaced or removed without following the agreed procedure.
- Status accounting and reporting - The lifecycle of a component is classified into different stages. For example: development or draft, approved and withdrawn. The stages that different types of CIs go through must be properly documented and the status of each CI must be tracked.
- Verification and audit - SACM conducts audits to ensure that there are no discrepancies between the documented baselines and the actual situation; and that release and configuration documentation is present before the release is rolled out.
Inputs and outputs Updates to assets and CIs are triggered by RFCs, service requests and incidents.