Time management in distributed factory simulation, a case study using HLA

Distributed simulation is attractive for modeling large scale manufacturing systems. However, synchronization requirements present distinct challenges in designing and implementing a suitable modeling structure. Our experience in building a distributed simulation model for 300mm wafer fab using the high level architecture (HLA) shows that time management should be considered at both the design and the implementation stages. This paper proposes an optimistic-conservative synchronization scheme by using model specific information at the implementation stage. Computational results are then presented to show that properly implemented distributed factory simulation can achieve significant reduction in model execution time.