Lot splitting is the operation of dividing a parent lot into smaller child lots for parallel processing, experimentation, or expedited movement - it increases routing flexibility but adds genealogy and control complexity.

What Is Lot splitting?

• Definition: Controlled separation of wafers from one lot into two or more tracked child lots.
• Common Purposes: Parallel routing, engineering experiments, partial expedite, and risk containment.
• Data Requirement: Must preserve full parent-child genealogy and disposition traceability.
• Operational Impact: Changes queue behavior, batching efficiency, and downstream merge needs.

Why Lot splitting Matters

• Cycle-Time Flexibility: Enables selective acceleration of urgent subset wafers.
• Learning Speed: Supports A and B experimentation across different tools or conditions.
• Risk Isolation: Limits exposure when testing uncertain process changes.
• Complexity Cost: Increases tracking burden and potential merge or synchronization delays.
• Quality Governance: Requires strict identity and route control to avoid mix-up errors.

How It Is Used in Practice

• Split Criteria: Define when splitting is allowed by product type, urgency, and process stage.
• Genealogy Controls: Enforce robust lot relationships in MES for full traceability.
• Post-Split Planning: Coordinate dispatch and optional merge logic to minimize downstream disruption.

Lot splitting is a powerful but high-governance operations tool - when applied selectively, it improves flexibility and response speed without compromising traceability integrity.