While supporting Documentum, there can be a complex situation where we have to rename the user and reassign all objects where user was the owner or a participant to the new name. Following are the list of objects which needs to be changed.
ACL (Active control List)
Alias Set
Sysobjects
Workflow and related objects
Routers
Activities
Workflow
Workitem
dmi_queue_item
Groups
dm_registered
dm_type
dmi_type_info
All these things except last 3 can be changed at one shot using “Reassign” tool of Documentum Administrator. The last 3 items needs to be reassigned manually. The process for using reassign tool is as in below.
Process
The process which can be used to rename the user is described in below flowchart. It is a two step process. In step1, we will analyze the effects of renaming the user.

Step-1
In step2, we will go ahead and rename the user.

Step-2