Transients of Synchronous Serial Production Lines with Non-Exponential Reliability Machines

Abstract

While smart manufacturing is viewed as the future of manufacturing, core knowledge about manufacturing is still lacking in various areas and will continue to be one of the main challenges in research and development. In terms of manufacturing process flow, to be able to make justified production control decisions, it is necessary to be able to predict the system's performance and the effects of control actions on the part flow. This amounts to knowing the transient behavior of the production system. However, most of the available studies on production system transients assume Markov models, while the actual production practice often deviates from this assumption. Therefore, in this paper, we carry out preliminary investigation of the transient behavior of production systems with machines characterized by non-Markovian reliability models. Specifically, using discrete-event simulations, we study serial production lines with machines' up- and downtimes modeled by gamma random variables. System properties of several performance metrics during transients are then discussed based on numerical experiments and a Control Theory-based approach. We view this as a first step in understanding the transient behavior of production systems under more realistic mathematical models.