A Work Item can be run under any tab of the Sentinel Control Center.
A Work Item can be processed while still in a Group and not acquired by a user. However, once a step is completed and the next step is of the same group, the step are acquired by the user.
After acquiring a Work Item steps in succession that belong to a Group and has been acquired by a user, the Work Item stays with the user.
If a single of succession of steps are with a user followed by a step of another group and returns back to the original role, the step does not revert to the user. It is assigned to the group.
The two stages of processing a work item are
Accepting a work item
Completing a work item