What is Entity

In this chapter the authors describe a program system that implements a Discrete Event Simulation (DES) development environment. The simulation environment was created using the LabVIEW graphical programming system; a National Instruments software product. In this programming environment, the user can connect different procedures and data structures with “graphical wires” to implement a simulation model, thereby creating an executable simulation program. The connected individual objects simulate a discrete event problem. The chapter describes all simulation model objects, their attributes and methods. Another important element of the discrete event simulator is the task list, which has also been created using task type objects. The simulation system uses the “next event simulation” technique and refreshes the actual state (attribute values of all model objects) at every event. The state changes are determined by the entity objects, their input, current content, and output. Every model object can access (read) all and modify (write) a selected number of object attribute values. This property of the simulation system provides the possibility to build a complex discrete event system using predefined discrete event model objects.