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

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

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.