To understand the concept you must know some terms which are commonly used in Pharmaceutical Manfacturing companies :
When ever such terms apply or applicable or found in a system or documented you use change control.
[b]To work satisfactorily under a GMP system with out having any problems you will implement Change Control system which performs following functions:
Capture the intent of the change.
Evaluate the effects of the change.
Authorize the change.
Record the facts about the change and the new status.[/b]
In a manufacturing organization, the levels of management and their impact on change are as follows:
[b]Senior management — numerically few; may ask for change, but rarely actually make changes.
Quality departments — numerically larger; audit, monitor and to some extent control change, but again, do not actually make changes.
Engineering departments — frequently smaller than quality departments; prone to making changes during design and construction, but less so postvalidation.
Operation and maintenance departments — numerically large; on site four times as long as quality department, and potentially the greatest engine for change in operational plants.
Process changes: When intended quality parameters are not met as per preapproved specifications that were transfered either from R&D or by Quality unit, changes in process parameters are bound to happen. These are either in scale-up phase or during manufacturing phase. These are to be effectively implemented thru a robust change control system.[/b]
Any deviation is a change and it should be initiated by Change control system.
This is a serious business for Global Multinational facilities who have facilities in multiple places and other continents under different Regulatory systems. To know, Understand, reason and question why such changes happened is necessary for the parent organization.