GOALI: Transients of Production Systems: Theory and Applications for Real-Time Productivity Improvement

生产系统的稳态性能指标，如生产能力和在制品，已经被定量地分析了50多年。相比之下，暂态特性，即达到稳态的过程，却很少受到关注。然而，瞬变具有实际意义：一些生产系统在开始轮班操作时所有缓冲区都是空的，这会导致由于瞬变而造成的吞吐量损失。因此，对此类损失的分析和最小化具有重要的工业意义。显然，对瞬变现象的研究也具有重要的理论意义。该项目的目标是开发一种从瞬变的角度分析和设计生产系统的理论，并将该理论应用于汽车行业的生产率提高。本项目的理论部分将通过研究描述现有系统的马尔可夫转移矩阵的第二大特征值(SLEs)和指数前因子(PEF)来进行。GALI项目的应用部分将在通用汽车S装配和发动机厂进行。该项目的智力价值在于建立了生产系统研究的新范式(基于SLES和PEF)，并开创了制造工程的新方向。使用系统论技术研究生产系统的瞬变。该项目的更广泛影响是为工业受众提供了一套工具，通过管理和优化生产系统的瞬变过程，并通过让研究生接触工厂车间运营的现实，来提高生产率。这些活动将由P.I.提供工业短期课程，并将这项研究的结果纳入P.I.最近出版的第二版教科书--《生产系统工程》。

The steady state performance measures of production systems, such as the throughput and work-in-process, have been analyzed quantitatively for over 50 years. In contrast, the transient properties, i.e., the process of reaching the steady states, received very little attention. The transients, however, are of practical importance: Some production systems begin their shift operation with all buffers being empty, which leads to throughput losses due to transients. Therefore, analysis and minimization of such losses are of industrial importance. Clearly, the study of transients is of theoretical importance as well. The goals of this project are the development of a theory for analysis and design of production systems from the point of view of the transients and the application of this theory for productivity improvement in the automotive industry. The theoretical part of this project will be carried out through the study of the Second Largest Eigenvalues (SLEs) and Pre-Exponential Factors (PEFs) of the Markov transition matrices that describe the systems at hand. The application part of this GOALI project will be carried out at GM?s assembly and engine plants.The intellectual merit of this project is in establishing a new paradigm in production systems research (based SLEs and PEFs) and initiating a new direction in manufacturing engineering ? that of investigating production systems transients using system-theoretic techniques. The broader impact of the project is in offering industrial audiences a set of tools for productivity improvement by managing and optimization of production systems transients and by exposing graduate students to the realities of factory floor operations. These activities will be facilitated by industrial short courses to be offered by the P.I. and by including the results of this research in the second edition of the textbook ?Production Systems Engineering?, recently published by the P.I.