lot splitting

**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.