A Global Wip Oriented Dispatching Scheme: Work-Center Workload Balance Without Relying on Target Wip

Work-in-process (WIP) oriented dispatching rules have been widely applied to balance workload for work-center in wafer fabs. The performances of WIP oriented rules, e.g., minimum inventory variability scheduling (MIVS) and WIP control table (WIPCT), highly rely on the accuracy of target WIP, as the target WIP plays a major role in measuring the pull request of work-center. In this paper, to replace the target WIP, we propose a workload indicator (WI), which utilizes global fab information like dynamic workload of work-center, batch size, setup requirement and lot status, to measure the pull request of work-center. Furthermore, the proposed WI is applied in a global fab dispatching scheme which considers K-machine look ahead and J-machine look back. Simulation results show its significant improvement versus the use of the target WIP oriented rules.