rolled throughput yield optimization

**Rolled throughput yield optimization** is the **system-level improvement of cumulative first-pass success across all process steps in a manufacturing chain** - because RTY is multiplicative, small losses at many steps compound into major end-to-end inefficiency. **What Is Rolled throughput yield optimization?** - **Definition**: RTY is the product of first-pass yields for each sequential process step. - **System Insight**: A process with many steps requires very high local FPY to maintain strong overall throughput. - **Sensitivity**: Bottleneck and high-fail steps dominate RTY decline and should be prioritized. - **Output**: True end-to-end quality efficiency metric independent of downstream rework recovery. **Why Rolled throughput yield optimization Matters** - **Compounding Effect**: Even 99 percent local yield can produce poor chain yield when step count is large. - **Improvement Prioritization**: RTY decomposition identifies the few steps with largest global impact. - **Factory Economics**: Higher RTY cuts WIP, cycle time, retest load, and hidden manufacturing cost. - **Planning Accuracy**: RTY-aware forecasts improve capacity and delivery commitment realism. - **Cross-Functional Alignment**: Encourages local teams to optimize for end-to-end flow, not isolated metrics. **How It Is Used in Practice** - **Step Mapping**: Calculate FPY for each operation and compute cumulative RTY baseline. - **Leverage Ranking**: Prioritize steps by marginal RTY gain per improvement effort. - **Closed-Loop Control**: Recompute RTY after each intervention and update optimization backlog. Rolled throughput yield optimization is **the system view that converts local quality gains into global factory performance** - sustained RTY improvement is a multiplier on cost, speed, and delivery reliability.