Probabilistic dispatching method and arrangement

摘要

A probabilistic dispatching method and arrangement for directing the movement of wafers in a manufacturing process. In a manufacturing process, some process steps may be performed by tools at alternate locations. Delivery of the material from one manufacturing process step to the next occurs via a rail for transporting the material and stockers for holding the material until the processing can commence. While awaiting processing, material may be moved from one stocker to a stocker at an alternate location and then removed for processing. A distribution of removal events is maintained for process steps having alternate locations, wherein a removal event refers to removal of material from a stocker for processing. When material is returned to a stocker for delivery to another stocker to await a subsequent processing step, the other stocker is identified as a function of the distribution of removal events for the subsequent processing step.