A change control system is any system that has been implemented that serves the essential purpose of assuring that the process of making changes is not done arbitrarily and without thought but rather is carefully considered and ultimately signed off on by a responsible party. The change control system typically encompasses not only the specific elements involved in ultimately making the decision to approve, reject, or postpone any changes, but also all of the processes that should be utilized in the process. For example, some of the elements involved in a properly functioning change control process can include, but are not necessarily limited to, previously documented Change Control Policy, an established Change Control Board, an established core of Change Management Tools, and in some cases a Quality Assurance team and an Asset Management Team. The Change Control System, in addition to providing as established policy for the routine process of making changes, should also have in place provisions for emergency changes which may arise.
This term is defined in the 3rd and the 4th edition of the PMBOK.