WBS and triggering event

[Cristiana D'Agosto]

Dear workflowers,
I am not sure how to trigger a workflow for the scenario described below;=20
I am not sure if I should try to raise the event using message control or=20
status changes? I haven't raised events these way before, would you be=20
able to help?
If a time confirmation is entered against a work order that is linked to a =
 
WBS element (via the additional data screen) and the calculated actual=20
costs of the time confirmation exceed the budget amount for the object an=20
error is produced.  The person entering the time confirmation (tx code=20
IW41) is able to exit out of the error log screen and is able to save the=20
confirmation.=20
Whilst the confirmation has been saved the actual costs are not reflected=20
in the work order's actual cost data nor are they represented in any of=20
the control reports available for the project.
The problem does not affect orders that have a reference to a WBS element=20
in their settlement rule.  However an error is generated at the time of=20
settlement.
It is a business and functional requirement for employees to be able to=20
book their time to work orders.  It is not appropriate that the processing =
 
of time confirmations be aborted as a result of the actual costs exceeding =
 
the available budget.
It has also been highlighted that the appropriate people to resolve these=20
errors are the supervisor of the employee who performed the work and the=20
person responsible for managing the project.  For this to occur there is a =
 
need for a workflow to be triggered when such an error occurs i.e. trigger =
 
a workflow when error BP 603 happens.
Any suggestions on how to approach this one? Which are the status object=20
types related to PS? Any user exit that I could use to trigger the event?
Any help would be very much appreciated!
Thanks and regards
Cristiana