provides a means to provision various resources, including the ability to track the usage of those resources and to de-provision items as necessary. To provide these services, the solution needs to hold pointers to the relevant data within the other systems it interacts with. Fortunately, the majority of information is stored in a single repository, Active Directory (NTDS).

Within the NTDS database, each item is assigned a unique Globally Unique Identifier (GUID). This GUID is used as the glue that joins the databases (Resource Manager and Plans Database) to the NTDS.

The relationship between the data stored in and the NTDS is very important to the correct operation of the Microsoft Provisioning System (MPS). Without this relationship, it may not be possible to create, update or delete items.

The following table lists some of the common system behaviors that can cause the GUID reference to change in the NTDS.

Table: System Behaviors and Their Impact on GUIDs

Account type	Actions	Impact on GUID
Users/Group/ Distribution list	Renaming the account	GUID unchanged.
Users/Group/ Distribution list	Change Exchange attributes such as proxy addresses, group membership, and display name.	GUID unchanged.
Users/Group/ Distribution list	Removal and recreation via delete.	New GUID allocated and link lost.
Users/Group/ Distribution list	New item created outside of MPS.	New GUID and no link recorded.
Users/Group/ Distribution list	Removal of an item outside the Provisioning Engine.	GUID reference remains in database and can not be removed.
Users/Group/ Distribution list	Object Restored.	GUID unchanged, Database is not updated.
Exchange Information Store	Store renamed.	GUID remains unchanged.
Exchange Information Store	New store created and mailboxes moved to that store.	New store GUID and link between plan and stores is lost.
Exchange Information Store	Known store restored.	GUID remains unchanged.

As demonstrated by the information in the previous table, most operations do not modify the GUID once the item has been created. However, if a GUID were to be changed, the link between the database and the NTDS would be lost. This loss can result in a number of issues. Should such a loss occur, it is important to contact Microsoft Support for the best way to resolve this issue.