work-in-process tracking

**Work-in-process tracking** is the **continuous monitoring of all lots currently inside the manufacturing system, including location, stage, and waiting status** - it provides the control foundation for throughput and cycle-time management. **What Is Work-in-process tracking?** - **Definition**: Real-time visibility of active WIP inventory across process steps and transport states. - **Tracking Dimensions**: Quantity, location, route position, queue age, and priority class. - **System Interfaces**: Combines MES lot status, AMHS movement data, and tool queue information. - **Analytical Use**: Supports bottleneck identification and dynamic dispatch decisions. **Why Work-in-process tracking Matters** - **Flow Balance**: Detects starvation and congestion conditions before they propagate. - **Cycle-Time Reduction**: Aging and queue visibility enables targeted intervention on delayed lots. - **Capacity Utilization**: Helps align WIP release with actual tool availability. - **Delivery Reliability**: Better WIP control improves due-date predictability. - **Financial Visibility**: WIP represents significant tied-up inventory value in fabs. **How It Is Used in Practice** - **Aging Dashboards**: Monitor queue age and risk-state thresholds by route segment. - **Priority Control**: Apply dynamic release and dispatch rules using current WIP distribution. - **Exception Workflow**: Escalate stalled or misrouted WIP for rapid correction. Work-in-process tracking is **a core operations control capability** - accurate WIP visibility enables faster flow decisions, lower cycle time, and stronger on-time production performance.