Virtual factories: an object-oriented simulation-based framework for real-time FMS control

Increasingly, automation and computer-based control play key roles in the operation of manufacturing systems. These two factors are necessary to support trends towards greater product customization and increased emphasis on reduction of lead times. At the same time, though, automation and computer-based control can be enormously expensive to design and implement in a factory. These high costs motivate the need for modeling and analysis. Existing modeling and analysis tools are effective for high level modeling of manufacturing systems. However, they suffer from limitations which are important in detailed analysis of system performance. This research is motivated by the need to develop modeling tools which support rapid development of detailed simulation models to assess system performance. The fundamental idea is to develop such an environment (i.e., a "virtual factory") which one may use to test different system configurations and control policies. We demonstrate our work thus far by presenting a case study involving deadlock avoidance in a semiconductor cluster tool.