System dynamics identification through element flow reasoning

Abstract

Dynamic issues always occur in systems such as production lines, logistic systems, traffic systems, etc. To have a clear understanding of the overall operating status of a system is important if the appropriate response is to be triggered because even some small fluctuations can have a significant influence on the associated functions. However, it is very difficult to replicate real-life operations exactly by any modeling technique. In this research, a methodology has been established to reason the system's behaviors in a dynamic manner by examining the characteristics of selected element flow streams. The concept is based on the top-down approach that contains three stages. The first stage is to identify the element flow streams such that they are able to represent the system and the second stage is about the transformation of measuring data into graphical patterns based on the proposed algorithms. In the final stage, a reasoning scheme is employed to extract the information embedded in the graphical patterns so that the system condition can be understood. For experimental purpose, a software program has been coded with the use of DLL to provide better portability. Typical cases such as Overflow, Normal, Slowdown, Blocking, and Unknown Event Occurrence were tested. It was observed that the proposed methodology was able to assist the system condition recognition. In terms of hardware requirements, only simple counting devices are needed and it is comparable to the Japanese's ANDON system but the human intervention factor can be reduced. To certain extent, the decision making process will have a good potential to be further automated with the application of the proposed methodology.