Parameterized Activity Cycle Diagram and Its Application

Abstract

The classical activity cycle diagram (ACD), which is a bipartite directed graph, is easy to learn and use for describing the dynamic behavior of a discrete-event system. However, the complexity of the classical ACD model increases rapidly as the system size increases. This article presents an enriched ACD called the parameterized ACD (P-ACD). In P-ACD, each node is allowed to have parameter variables, and parameter values are passed to the parameter variables through a directed arc. This article demonstrates how a single PACD model can be used to represent an entire class of very large-scale systems instead of requiring different ACD models for every instance. We also illustrate that the well-known activity scanning algorithm can be used to execute a P-ACD model. A prototype P-ACD simulator implemented in C# programming language is provided, and an illustrative example of a conveyor-driven serial production line with the prototype simulator is presented to illustrate construction and execution of a P-ACD model. In addition, it is demonstrated that the proposed P-ACD allows an effective and concise modeling of a job shop, which was not possible with the classical ACD.