How to Avoid Hard Coding Variables in Your Simulation Model

The purpose of this paper is to demonstrate the ability of AutoMOD as a flexible modeling tool. Simulation models of material handling systems like those found in automotive paint shops & assembly systems often require many variables, conveyor speeds, and complex logic. These systems have many different variables associated with them. The most important ones are: conveyor speeds, carrier counts, routing information, floating carrier numbers between two control points, active and inactive station information, station operation times, and shift schedules. In order for a simulation analyst to control or experiment with a material handling system, he or she will usually have to vary one or more of these variables. In the past, this has meant that these “hard-coded” variables would have to be changed one by one through menus for each material handling segment or system. Other methods including the use of AutoStat or AWK could be used to change certain parameters without having to visit the edit menus in AutoMOD. This paper will address how users can use external data files to control these traditionally “hard-coded” variables, thereby allowing simulation analysts and their customers to drive their material handling systems as they have traditionally used external files to provide process information for their models. PMC’s approach was to create a flexible and robust model that imports all of these system parameters from external data files. This allows for an increase in model efficiency if model experimentation is large and involves many different physical changes. Using this method, a potential customer can modify these parameters for experimentation with a run-time version of AutoMOD simulation software.