WSC 2005

WSC 2005 Final Abstracts

General Applications D Track

Monday 3:30:00 PM 5:00:00 PM
General Applications III

Chair: Sam Jansen (University of Waikato)

Packaging Capacity Analysis of a Biopharmaceutical Production Operation
Steve Chu and Prasad V. Saraph (Bayer HealthCare) and Lee Schruben (University of California)

This paper discusses an application of discrete event simulation in analyzing packaging capacity at Bayer Corporationís Berkeley, California facility. A discrete event simulation model was used to estimate output under differing employee staffing and scheduling policies, taking into consideration product and equipment requirements. This model was also used to study the effects on packaging operations due to changes in the manufacturing environment. The model and its recommendations were used to support a major business process decision.

Simulation with Real World Network Stacks
Sam Jansen and Anthony McGregor (University of Waikato)

Network simulation is used widely in network research to test new protocols, modifications to existing protocols and new ideas. The tool used in many cases is ns-2. The nature of the ns-2 protocols means that they are often based on theoretical models that might not behave in the same way as real networks. This paper presents the Network Simulation Cradle which allows real world network stacks to be used in a wrapper that allows the stacks protocols to be used in the ns-2 network simulator. The network stacks from the open source operating systems Linux, FreeBSD and OpenBSD are included in the simulation cradle as well as a stack designed for embedded systems, lwIP. Our results show that ns-2's TCP implementations do not match observed behaviour from real machines in some respects and using the Network Simulation Cradle produces results closer to real world network stacks.

Queuing Models of Vehicle-based Automated Material Handling Systems in Semiconductor Fabs
Dima Nazzal and Leon F. McGinnis (Georgia Institute of Technology)

This research explores analytical models useful in the design of vehicle-based Automated Material Handling Systems (AMHS) to support semiconductor manufacturing. The objective is to correctly estimate the throughput and move request delay. The analysis approach is based on queuing network models, but taking into account details of the operation of the AMHS. We analyze the vehicles movement in the system using a Markov chain. This analysis provides the essential parameters such as the blocking probabilities in order to estimate the performance measures. A numerical example is provided to demonstrate and validate the queuing model.