Research Initiation: Two-Level Performance Analysis of Cellular Manufacturing Systems

该项目的目标是为单元制造系统开发一个两级性能模型，其中单元通过材料处理系统（MHS）连接，原材料和未完成的部件存储在自动存储/检索系统（AS/RS）中。每个单元本身是一个工作站网络，共享一个公共有限的存储空间和一个加载/卸载站。这些工作站通过一个物料处理单元连接起来。该模型在一个层次上对单个细胞、MHS和AS/RS分别进行分析。（这些组成部分之间的相互依赖关系反映在分析中。）然后在第二级中利用这一层的结果来定义一个站点聚合网络，每个站点代表一个小区、MHS或AS/RS。然后，这个网络被分解成子网，这是基于最初由首席研究员引入的概念。两个级别之间的相互关系需要迭代数值技术，以便计算不同的性能度量。从建模的角度来看，该模型有两个重要的贡献：(1)它明确地考虑了MHS和AS/RS；(2)它考虑了不同的调度策略，因此在一定程度上反映了系统的动态特性。从应用的角度来看，该模型可以在不同的情况下使用，从单个单元的分析到大规模网络类型制造系统的分析。

The objective of this project is to develop a two-level performance model for cellular manufacturing systems where the cells are connected via a material handling system (MHS) and raw material and unfinished parts are stored in an Automatic Storage/Retrieval System (AS/RS). Each cell by itself is a network of workstations sharing a common finite storage space and a load/unload station. These workstations are connected via a material handling unit. The model is such that in one level the individual cells, the MHS and the AS/RS are each analyzed separately. (The interdependency among these components is reflected in the analysis.) The results from this level are then utilized in a second level in order to define an aggregated network of stations each representing a cell, the MHS, or the AS/RS. This network is then decomposed into subnetworks based on a concept originally introduced by the Principal Investigator. The interrelationship between the two levels requires an iterative numerical technique in order to compute different performance measures. From a modeling perspective, the model makes two significant contributions: (1) it explicitly considers the MHS and the AS/RS, (2) it accounts for different scheduling policies and, therefore, reflects the dynamic nature of the system to some degree. From an application perspective, the model may be used in different circumstances, ranging from the analysis of an individual cell to the analysis of a large scale network type manufacturing system.