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.