The change control practice typically consists of different procedures (this list may vary slightly):
- Change request logging;
- Change planning;
- Change authorization;
- Change scheduling;
- Change implementation;
- Change closure.
Change types
Change Control supports three types of changes: standard, normal and emergency change. The change type determines which state model is used and the change process that must be followed.
Standard Change
A standard change is a pre-authorized change that is low risk, relatively common and follows a specified procedure or work instruction.
Changes of this type are most frequently implemented, have repeatable steps and were successfully implemented earlier. As Standard changes are pre-approved, they follow the process in which authorization steps are not required.
Approved standard change requests can be predefined as a template in the appropriate catalog to make requesting a change more efficient. Also, this capability allows the team to control the changes that are authorized as standard.
Emergency Change
A change that must be implemented as soon as possible, for example, to resolve a major incident or implement a security patch.
The cases where emergency change is suitable are (for example):
- Fix the current fail situation or retroactive where the impact has already been experienced;
- Fix the fail situation where the negative impact is invariable if action is not taken.
The priority of the emergency change allows it go straight to the Authorization state, for approval by the CAB group.
Normal Change
Normal change is any service change that is not a standard change or an emergency change.
Generally, the process of the change requests of such type prescripts two levels of approval before implementing, reviewing, and closing.
These changes require a full range of evaluations and authorizations, such as: technical approval; Change Advisory Board (CAB) authorization; change manager authorization; and others. Normal changes planning foresees at least possible disruption to service, so these changes often scheduled outside change blackout windows or during defined maintenance windows. This type of changes is used to implement profitable change for any service that is not a standard or emergency change.
