lot merging
**Lot Merging** is a manufacturing operation that combines multiple smaller lots into a single larger lot for processing efficiency or scheduling optimization.
## What Is Lot Merging?
- **Purpose**: Reduce setup time by processing similar lots together
- **Tradeability**: Merged lots may lose individual identity
- **Risk**: Contamination or quality issues affect larger quantity
- **Tracking**: Requires careful genealogy documentation
## Why Lot Merging Matters
In semiconductor fabs, equipment changeovers can take hours. Merging compatible lots maximizes equipment utilization but complicates traceability.
```
Before Merging:
Lot A: 25 wafers (Customer X)
Lot B: 20 wafers (Customer Y)
Lot C: 30 wafers (Customer X)
After Merging:
Lot A+C: 55 wafers → Process together (same customer)
Lot B: 20 wafers → Process separately
Setup time saved: 1 changeover eliminated
```
**Merge Criteria**:
- Same product specification
- Compatible priority levels
- Within acceptable date range
- Same quality requirements
- Customer approval (if required)