Optimization of Multiclass Queueing Networks

9610486个Bertsimas多类排队网络为制造业和计算机通信系统提供了丰富的模型类。评估和改进这类系统性能的实际需要促使人们对这些模型的分析、优化和稳定性进行了广泛的研究。这一研究将为多类排队网络分析中几个公开问题的求解方法的发展做出贡献。具体地说，研究人员将研究可变性、转换时间和一般保持时间分布对这些网络的最优性能的改进界限的影响。这项研究借鉴了一种基于数学规划的方法(可达域法)来进行随机系统的性能优化。研究的总体目标是基于从可达区域方法得到的松弛来推导具有次最优性保证的启发式调度策略。多级排队网络在计算机和通信领域已被证明是非常有用的，它们已经成为电信系统设计、分析和优化的首选模型。虽然到目前为止，它们作为制造系统模型的使用受到某些技术限制的阻碍，但这项研究专门讨论了潜在地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，从而使这些模型能够在制造系统中成功应用，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.