super hot lot
**Super hot lot** is the **highest-priority dispatch class reserved for urgent lots that must preempt normal scheduling flow** - it is used sparingly for mission-critical customer commitments or fab-recovery diagnostics.
**What Is Super hot lot?**
- **Definition**: Special lot category with top dispatch rank above standard hot-lot and normal production classes.
- **Operational Privileges**: Queue bypass, immediate transport preference, and setup preemption at eligible tools.
- **Typical Use Cases**: Fab-down root-cause samples, executive-priority customer prototypes, and severe delivery recovery cases.
- **Governance Need**: Requires strict approval workflow to prevent overuse and priority inflation.
**Why Super hot lot Matters**
- **Urgency Response**: Provides a controlled mechanism for handling exceptional business-critical situations.
- **Recovery Acceleration**: Speeds diagnostic cycles during major process or equipment incidents.
- **Delivery Protection**: Helps recover specific high-impact commitments under constrained capacity.
- **System Tradeoff**: Frequent super-hot overrides can degrade overall fab flow and increase tail cycle time.
- **Policy Integrity**: Strong controls are needed to keep priority classes meaningful and effective.
**How It Is Used in Practice**
- **Approval Controls**: Require high-level authorization with documented business and technical justification.
- **Execution Limits**: Cap active super-hot volume as a percentage of total WIP.
- **Impact Monitoring**: Track collateral delay to standard lots and adjust policy thresholds accordingly.
Super hot lot is **a necessary but high-cost scheduling exception** - disciplined, limited use preserves urgent-response capability without destabilizing overall production performance.