The project is considered successful, if it is completed on time and within budget.
— project management system

The introduction of any changes requires constant monitoring of performance throughout all phases. Changes may relate to objects, their software and hardware component, or their operation may affect the organization, as a whole or some of its parts, or may be related to upgrading equipment, processes, data, positions, drawings and documentation. Change Control – a system of control of all aspects of the activity, when introducing changes

Change Control — allows not only to control the current status of implementation of changes, but also provides a centralized exchange of information between the participants, eliminating time delays, as well as reducing the time for the implementation of all stages.

In project management, Change Control is seen as a project management process in which project changes are presented and approved.
— essence of Change Control in one phrase