Completed tasks disappear only after a refresh of UWL cache

My aim of writing this Wiki article is to let the users get acquainted with the functionality of the UWL.

Whenever a user performs some action on a work item in the Universal Work List, the item does not disappear immediately.

Rather it is removed from UWL after a refresh of the UWL cache. This often confuses the user because he gets a screen dump if by mistake, he re-opens that work item and performs some action. The error seems something like :

Critical Error
A critical error has occured. Processing of the service had to be
terminated. Unsaved data has been lost.
Please contact your system administrator.

Work item 000001971399 already has status COMPLETED

The update/removal of a processed task in the UWL depends upon what kind of task it is.  Some task processing screens are more integrated with the UWL and include refresh triggers. 

For  example, if you create an ad-hoc task, open it up from the UWL in the UWL viewdetail iview and  complete/approve it, you will automatically be taken back to  the UWL with an immediate refresh so that the task is disappeared (or status is updated).  However, for some other task types, the nature of their launch mechanism won't allow for this refresh trigger.  An example of this would be tasks processed  via the SAPGUI. 

The SAPGUI doesn't know where the user came from or where the user is going back or navigating to,  so it can't force the UWL to refresh, but one thing it does is to update the task status in the  backend.  Therefore, the UWL will not get the
updated task status (compeleted, in process, forwarded,  etc) until the UWL performs a refresh.

Following are the workarounds which you may find helpful in this scenario :

1)Click the "refresh" button after you perform some action on a UWL work item. This will trigger a refresh of the UWL cache explicitly and the completed work item will disappear.

2)The UWL refresh interval is governed by the parameter "Default Cache Validity" which you can find under

Universal Worklist Service Configuration link under System Administration -> System Configuration -> Universal Worklist.

The default value is 5 minutes. However, in case you want the refresh to happen earlier, you can decrease the value of this parameter. Setting this parameter to 1 means that the UWL cache will be refreshed every minute and the tasks on which an action is performed already will be removed in shorter span of time.

Note ** - Since the refresh of the UWL cache is a resource intensive operation, in case the UWL is pulling out thousands of work items from many backend systems, setting this parameter less than 5 is not recommended. This can cause serious performance degradation of the UWL.

I am glad to see the comments and queries which some of you has put in here. You can mail me at nitin.mehra@sap.com in case you seek clarifications.