In many service desk workflows, a parent ticket is used to represent the underlying problem and once the parent ticket is resolved, the individual instances of the problem need to get updated.

Examples:

• ITSM/ITIL: Many Incident reports may occur when a system is unavailable. This handled by another team as a single Problem issue. When the underlying Problem is solved, the linked Incident tickets should automatically get a comment alerting the agent that they can close the issue - or even just automatically close the Incident issues on behalf of the agent.
• Developer/Application Support: Many Support Requests may occur when users hit a certain problem, eg. they can't log in. This may be recorded in a Development project as a Bug. Once the Bug is fixed and the fix is deployed, the linked Support Requests should automatically get updated.