Optimization of Multiclass Queueing Networks

[9610486]伯特西马斯多类排队网络为制造业和计算机通信系统提供了一类丰富的模型。评估和改进这些系统性能的实际需要激发了对这些模型的分析、优化和稳定性的广泛研究。本研究将有助于发展多类别排队网络分析中若干开放性问题的求解方法。具体来说，研究者将研究可变性、转换时间和一般保持时间分布对这些网络的最佳性能的影响。该研究利用基于数学规划的方法（可达域方法）来优化随机系统的性能。研究的总体目标是基于可达区域方法的松弛导出具有次最优保证的启发式调度策略。多类排队网络已被证明在计算机和通信领域非常有用，它们已成为电信系统设计、分析和优化的首选模型。虽然它们作为制造系统模型的使用迄今为止受到某些技术限制的阻碍，但本研究专门解决了可以克服这些限制的问题。这项研究很有可能在一些极其困难的问题上取得重大突破，从而使这些模型在制造系统中的成功应用成为可能，尤其是在半导体制造领域。

9610486 Bertsimas Multiclass queuing networks give rise to a rich class of models for manufacturing, and computer-communication systems. The practical needs to evaluate and improve the performance of such systems have motivated extensive research efforts on the analysis, optimization and stability of these models. This research will make contributions to the development of solution methods for several open problems in the analysis of multiclass queueing networks. Specifically, the investigator will study the effects of variability, changeover times, and general holding-time distributions in developing improved bounds on the optimal performance of these networks. The research draws on a mathematical programming-based approach (the achievable region approach) to performance optimization of stochastic systems. The overall objective of the research is to derive heuristic scheduling policies with sub-optimality guarantees based on relaxations derived from the achievable region approach. Multiclass queueing networks have proved quite useful in the computer and communications field, where they have become the models of choice for design, analysis, and optimization of telecommunications systems. While their use as models for manufacturing systems has thus far been impeded by certain technical limitations, this research specifically addresses issues that can potentially overcome these limitations. The potential is high that this research will lead to significant breakthroughs on some extremely difficult problems, thereby enabling the successful application of these models in manufacturing systems, most notably in the area of semiconductor manufacturing.