The purpose of the Change Management process is to ensure that standardized methods and procedures are used for handling any changes to IT infrastructure. Changes to infrastructure may arise reactively in response to problems or a service fulfilment request or pro-actively to improve IT services. Change Management process is used to minimize any incidents on account of the change.
A change management process ensures that a change request is recorded and then evaluated, authorized, prioritized, planned, tested, implemented and documented in a controlled manner.
An example of change management could be the upgrade of an application or change in hardware etc.
Typically change management is triggered from Problem Management or Service Request which requires change in infrastructure for resolution.
A key concept is the Change Advisory Board (CAB) which is constituted with representation from all the impacted functional groups in IT. The CAB reviews the impact, plan and provides the approval for the change before it can get implemented.