Change Management - in projects
Change Management means many things to many people.
In the context of large engineering projects, it is a project management process to control how decisions are made as to whether - or how - a change to the scope of work (SOW) of a contractor should be implemented, to ensure that the consequences - in terms of cost, schedule, quality, HSE, etc are fully understood and considered.
It is closely related to the interface management process because a change to the scope of work of one contractor could lead to interface issues - or further changes - with another contractor. Conversely, interface issues raised can lead to change proposals at one or both contractors.
Refer to ProjectChangeManagement.Org for more information about Project Change Management