Implementing manufacturing strategies for advanced capacity analysis and material handling design in the planning process of a wafer fab

The dimensioning of appropriate process equipment and material handling capacities for wafer fabs by means of simulation technique demands for an accurate prediction of the operational fab behavior. In order to get reliable data of maximum WIP and throughput of the fab, the implementation of the most crucial constraints and dispatching policies of the shop floor in the simulation model is an important prerequisite. This in turn is the information which is necessary for the fab design such as to designate storage capacities. Hence, future dispatching strategies should already be considered when performing simulation studies for the determination of process equipment capacities and the dimensioning of material handling systems. This gains even more importance for complex make-to-order manufacturing environments with a large quantity of process flows and strongly varying production orders. The paper points out the requirements of simulation models which are needed for an accurate analysis of process equipment and material handling capacities for highly complex wafer fabrication, especially in make-to-order manufacturing environment. The implementation of a customized manufacturing control strategy applied in the diffusion area for capacity modeling of process equipment and material handling is presented in detail.