Hybrid Models for Simulation-Based Prototyping of Decision Logic in Material Flow Systems

这笔赠款提供资金，以创建一个新的方法来离散事件模拟，一个计算工具，广泛用于设计和操作改进离散物流系统，如工厂和仓库。 这种新方法结合了两种现有的范例。 第一种是流程交互范式，它有效地对物料流、客户流或工作流进行建模，但在表示复杂的决策逻辑方面存在局限性。 第二种是事件调度范式，它用于对复杂系统建模，但在建模时间和工作量方面成本很高。 通过根据物理和决策逻辑特性对离散物流系统进行分类，将为不同类别的系统指定通用决策逻辑单元，使用事件调度来封装决策行为。 这些单元将与物理系统流的过程交互表示接口。 该研究将通过实验比较使用新的混合方法获得的结果与使用简单模型获得的结果，在系统性能的估计方面。 由于计算时间是仿真的主要关注点，因此该项目还将测量具有这样的决策逻辑单元的计算效果，与简单的系统表示法相比，该项目的成功完成以及由此产生的混合仿真建模方法将提高具有复杂决策逻辑的系统建模和分析的最新水平。 一个主要目标是提供更好的原型设计能力，在决策逻辑在当今日益复杂的系统中实现之前对其进行测试。 通过比较的混合方法对更简单的表示在各种系统类型，在建模的细节层次的效果的初步理解将实现。 其他预期成果包括对研究生和本科生教育的影响，以及向研究界提供的案例研究。

This grant provides funding to create a new approach to discrete-event simulation, a computational tool used extensively for design and operational improvement of discrete material flow systems such as factories and warehouses. This new approach combines two existing paradigms. The first is the process-interaction paradigm, which efficiently models flow of material, customers or work through a system, but has limitations in representing complex decision logic. The second is the event-scheduling paradigm, which is used to model complex systems, but is quite costly in modeling time and effort. By classifying discrete material flow systems according to physical and decision logic characteristics, generic decision logic units will be specified for different classes of systems, using event-scheduling to encapsulate decision-making behavior. These units will be interfaced with a process-interaction representation of the physical system flow. The research will experimentally compare results obtained using the new hybrid approach against those obtained using simpler models, in terms of estimates of system performance. Since computation time is a major concern with simulation, the project also will measure the computational effect of having such decision logic units, as compared to a simpler system representation.Successfully completed, this project and the resulting hybrid approach to simulation modeling methodology will improve the state of the art in modeling and analyzing systems with complex decision logic. One major goal is to provide a better prototyping capability, to test decision logic before it is implemented in today's increasingly complex systems. By comparing the hybrid approach against simpler representations across a variety of system types, an initial understanding of the effect of level of detail in modeling will be achieved. Additional expected results include impact on graduate and undergraduate education, and case studies made available to the research community.