Continuous models for production ows

We model high volume, multi-stage continuous production ow through a re-entrant factory. We approximate production volume through a continuous density variable and production stages through a continuous completion vari-able. Ideas from trac modeling and gas dy-namics are adapted to generate a hierarchy of PDE models. All of these models are variations of nonlinear nonlocal hyperbolic conservation laws. They allow extremely fast and accurate simulations. Large scale discrete event simula-tion based on an INTEL factory are presented. The data are analyzed to generate a param-eterization for the PDE model of this factory. A diusion coecient is determined by looking at the spread of throughput times in a factory run at steady state.