Entering Breakdown Data and Duration 
Use
If there is a functional breakdown due to a problem or the execution of an activity, you note this breakdown - depending on Customizing - in one of the following two places:
As a rule, when you create a notification, it is sufficient to enter the malfunction start in the notification header, and flag the field Breakdown. This indicates that the system is broken down at the time specified.
The breakdown data screen is relevant mainly for entering the breakdown end and the downtime.
Entries in the Breakdown Data Screen
The system calculates and displays the duration in the new unit of time. The unit entered when you save the notification is then valid for further processing of the notification.

If the downtime is already displayed and you subsequently change the malfunction start or end, the system recalculates the duration.