Jack Tree is the core technique of the Stackable Jacks Method. It organises Jacks into a cohesive hierarchical structure that provides full traceability between business needs, objectives, requirements and specifications. This technique is critical for a practitioner to master.

Purpose: Identify all essential elements of the scope and establish full alignment
Input: List of initial Jacks
Output: Hierarchical list of requirements
Mnemonic: TRACE

Jack Tree brings the “Why” to the centre by using User Story and Enabler formats to reveal missing needs, confirm objectives, surface alternatives and clarify context. It casually applies concepts and metrics from graph theory to define the rules for building a Jack Tree, represent requirement levels, and establish the qualities that make the Jack Tree a flexible and comprehensive tool.

Jack Tree provides an effective way to:

• analyse ambiguity
• identify implicit requirements
• generate alternative options
• build full traceability.

Beyond root cause analysis, the Jack Tree acts as a structured accelerator for delivery preparation. Its validated hierarchy allows practitioners to rapidly populate backlogs by directly transforming nodes into standard artifacts—such as System Requirements, persona-based User Stories, or rationale-based Enablers—ensuring that delivery items are traceable and estimation-ready from day one.

Jack Tree delivers the highest level of divergent Design Thinking within the Stackable Jacks Method. Building on the outputs of Jack Semantics and Jack Points, it produces the structured foundation used by Jack Semaphore, Jack Story, Jack Scenario and Jack Intent, and serves as the core element of the Stackable Jacks Requirements Framework.