Optimal Control and Performance Evaluation of Stochastic Service and Manufacturing Systems

拥塞发生在服务和制造系统中，对商品和服务的需求是随机的，处理或服务时间也是随机的。本研究的目的是通过随机建模和分析，找到有效的方法来减少拥挤。它将有助于随机服务和制造系统中的三个重要问题：（1）多目标服务系统的系统和政策设计;（2）公共和私人服务系统的竞争和协调;（3）随机冲击下生产系统的可靠性改进。 第一个问题（特别是与机场、边境口岸或癌症筛查系统的安全检查系统有关）将使用简单的排队网络结构来解决。两阶段排队网络（其中一些客户需要通过第二阶段）可以捕获系统的主要特征，其中最小化采样误差和等待成本的目标可以相互权衡。对于第二个问题，在实现最大的社会效益是主要目标，我们的系统模型与客户选择和社会规划师（政府）的干预两个通道排队网络。最后，第三个问题将利用更一般的冲击过程来模拟供应链中断。 与经典的排队应用相比，所提出的研究是创新的，在其使用的排队模型解决公共和私人服务提供商的协调和多个目标之间的关系，在随机服务系统。因此，这项研究的结果将与寻求设计服务或系统和/或控制政策以提高效率的公司和政府机构相关。 拟议的研究与加拿大-美国边境过境系统或机场安全检查站所面临的挑战高度相关。调查结果可以支持加拿大边境服务局等机构在有效管理边境业务、平衡安全和公共安全需求与有效旅行和贸易方面的工作。关于公共和私营服务系统的竞争和协调的工作与加拿大的保健系统密切相关。虽然加拿大的政治家们继续辩论双层公共和私人医疗保健系统的可行性（因为它们已经存在于澳大利亚和一些欧洲国家），但没有定量的拥挤分析来评估这样一个系统。我的研究成果可以为省级政府设计可持续和负担得起的医疗保健系统的能力做出重大贡献。最后，拟议的工作，在随机冲击下的生产系统的可靠性改进将有助于加拿大供应链组织与国际供应商或客户，以提高其公司在一个不确定的全球环境受到自然灾害和/或政治动荡的运营可靠性。

Congestion occurs in service and manufacturing systems with random demands for goods and services, and random processing or service times. The aim of this research is to find effective ways to reduce congestion via stochastic modeling and analysis. It will contribute to three important issues in stochastic service and manufacturing systems: (1) system and policy design for service systems with multi-objectives; (2) competition and coordination of public and private service systems; and (3) reliability improvement for production systems under random shocks. The first issue (particularly relevant with respect to security-check system at airports, border-crossings, or cancer screening systems) will be addressed using simple queuing network structures. A two-stage queuing network (where some customers are required to go through a second stage) can capture the main characteristics of a system in which the objectives of minimizing sampling errors and waiting costs can be traded-off against each other. For the second issue, where achieving maximum social benefit is the main objective, we model the system with a two channel queuing network with customer choice and social planner’s (government’s) intervention. Finally, the third issue will be addressed utilizing more general shock processes to model supply chain interruptions. Compared with classical queuing applications, the proposed research is innovative in its use of queuing models addressing the coordination of public and private service providers and the relation between multiple objectives in a stochastic service system. The results of this research will therefore be relevant to firms and government agencies seeking to design service or systems and/or control policies to improve their efficiency. The proposed research is highly relevant to the challenges faced by Canada-US border crossing systems or airport’s security checkpoints. Findings can support the work of agencies such as Canada Border Services Agency in managing border operations effectively, balancing security and public safety needs with efficient travel and trade. Work on competition and coordination of public and private service systems is highly relevant to Canada’s healthcare system. While politicians in Canada continue to debate the viability of a two-tier public and private healthcare system (as they already exists in Australia and some European countries), no quantitative congestion analysis for evaluating such a system exists. Outputs from my research can make a significant contribution to the ability of Provincial Governments to design sustainable and affordable healthcare systems. Finally, the proposed work on reliability improvement for production systems under random shocks will help Canadian supply chain organizations with international suppliers or customers to improve the operational reliability of their firms in an uncertain global environment subject to natural disasters and/or political turmoil.