Views:
Behavior:
When attempting to configure a workflow using the Modification Date/User system field as the workflow trigger, the workflow fails to commence after the document is edited and stored back into the system.

Solution:
For the workflow to commence as anticipated, the configured trigger would have to undergo an index change. The Modification Date/User fields are sometimes changed as a side-effect of other operations that would not be considered index changes. While you can have a trigger condition defined using the Modification Date/User system field, it will not trigger on every operation done that would modify it. An example would be merging annotations or editing a document; these operations will not trigger the workflow despite updating the field. 

The Modification Date/User system field would not be considered reliable for a workflow trigger as it would only trigger based on specific operations that would be considered an index field change.
It is recommended to use a user-created index field as any changes made will always be considered index field changes, thus triggering the workflow.

KBA is applicable for both Cloud and On-premise Organizations 
This article is valid for DocuWare versions: 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9 | DocuWare Workflow; Trigger Condition