ABAP update work processes are used to update records in the database. The update status of this records can be monitored in transaction SM13 which would also display failed updates. A failed update means that information that needed to be persisted in the database, was not stored successfully and hence is not available in the database. This can lead to inconsistencies and other errors down the road.
With SAP Focused Run you can monitor for failed updates and address the problem in a timely manner.