All kinds of changes can and should be recorded in the Change Management module. Some of them are listed as follows:
Change requested by the customer to add or deduct scope from his project: In this case you will use both sides of the Change Management (Budget and Commitment) and most of the phases as required.
Missing scope from your original estimate: If your organization missed some scope and therefore the change being tracked is considered "in the scope of the project," you will only use the commitment side of Change Management. You will be requesting your contractors to price out some scope that will increase their contract to accommodate for the scope.
Back charge to a contractor: A back charge will involve one or more contractors such that you will deduct money from one contractor and add it to another or to your contingency. This can end up being a net-zero change.
Time and material change: Time and material changes can also be tracked in the Change Management module...