KanbanGit/docs/releases/0.1-kanban-foundation/09-ticket-hierarchy-parent-child-relationships.md

09 Ticket Hierarchy and Parent-Child Relationships

Goal

Implement the parent-child ticket model, including nested parent trees and validation around which tickets are allowed to act as parents.

Requirements

• A ticket may have zero or one parent ticket.
• Only tickets of type Parent may be selected as a parent target.
• A Parent ticket may itself have a parent ticket.
• Task and all other non-Parent types may have a parent but may not act as a parent.
• Parent tickets must show their children in a structured list.
• Nested child structures must be visually understandable, for example through indentation.

Acceptance Criteria

• Assigning a non-Parent ticket as a parent is rejected.
• A Parent ticket can contain child tickets of multiple types.
• Nested parent chains are supported.
• The ticket detail view for a parent ticket shows its child tree.

Out of Scope

• Automatic roll-up calculations
• Dependency graphs
• Parent-based board grouping